Subtracting dates in stata. 1 or a fully updated version 14.

Subtracting dates in stata. I suggest (please) (a) giving a worked example with data you have and data you want (b) asking a friend with better command of English to rewrite: it's not grammatical or idiomatic. destring A, replace destring B, replace replace A = 0 if A==. value will be exactly the same if the data is sorted on the time (or panel/time) variable, and there are no time gaps in the data. I am using Stata. Historical Research: Calculate durations between historical dates for academic purposes. See [D] Datetime for an introduction to Stata’s date and time features. meesters@gmail. Within Id, I want to keep the observations of the dataset such that the "time distance" between "mm" of date1 and "mm" of date2 is the smallest. type dates1 We now handle birthdays relative to a given date, and dates relative to the month of a given date. Therefore I used following code. -search min- and -search max- would point you to them, although it wouldn't be immediately obvious which links to click on. There are a variety of built-in functions and manual processes you can then do to calculate your desired value. Feb 17, 2012 · I have a question about some of the internal workings for the Oracle DATE and INTERVAL datatypes. Every command of Stata is designated r-class, e-class, or s-class, or, if the command stores nothing, n-class. pope@gmail. Here's an example of my dataset: group event date A 1 08mar2013 A 2 10mar2013 A 3 15mar2013 B 1 10sep2012 B 2 15sep2012 C 1 07aug2011 C 2 23aug2011 C 3 23aug2011 C 4 24aug2011 D 1 25dec2012 E 1 01jan2013 I want to generate a new variable, say Step 3 – In the command window, issue the following commands to convert the Excel date variable (that fails to import as a date variable) into a Stata date variable that is a bona fide date variable. But in recent versions of Stata, there is a function age() which does that directly, and is smart about leap years. These methods are super simple and easy to use. We now handle birthdays relative to a given date, and dates relative to the month of a given date. Dealing with Dates in STATA Dates in your research STATA can help you manipulate dates Add, subtract, calculate time between dates Comparing dates (e. This process is particularly important when working with variables like age, anatomical injury, physiological derangement on admission, and pre-injury comorbidity. Perform the subtraction of the dates using the subtract function or formula. com> Re: st: extract hours, minutes and seconds from date From: Maarten buis <maartenbuis@yahoo. How do I do this? Example and analysis of the problem Let us be clear about what May 4, 2022 · Thanks, I used it as replace Desired_date = Desired_date+cofd (1) and it worked! Can you please suggest how to subtract these datetimes to get number of days? (for different set of datetime variables) Nov 27, 2017 · For the sake of future reference: From Stata's understanding, you don't have a date variable, but a string. This is convenient when you need to calculate the number of days between patient appointments, for example. We will cover various topics, including understanding Stata date formats, converting dates, formatting date variables This article covers all the basics of working with dates in Stata. 3. Step-by-step guide for calculating date differences with examples and solutions. daily to monthly date variable), and some other related commands. ac. d@att. Can someone please help? Sep 23, 2022 · The operators defined in Stata are given in the table below: Stata has many mathematical, statistical, string, date, time-series, and programming functions. com> Re: st: Subtracting in Variable by a Group From: Nick Cox <njcoxstata@gmail. This guide covers storage, conversion, extraction, and duration calculations. threshold extends linear regression to allow coefficients to differ across regions. SIF dates are convenient because you can subtract them to obtain time between dates, for example, datetime2 datetime1= milliseconds between datetime1 and datetime2 (divide by 1,000 to obtain seconds) date2 date1 What version of Stata are you using (version/flavor/build#)? what are the formats of the variables? data storage types? what's the origin of the dataset? (manually inputted, loaded as dta, converted from other file type, etc) Try discarding formats and subtracting the dates. date group price 2010m1 1 10 2010m2 1 15 2010m3 1 12 2010m1 2 9 2010m2 2 21 2010m3 2 15 2010m1 3 8 2010m2 3 20 2010m3 3 16 For instance, if I want to subtract group 1's prices from group 3's prices, the new variable should be the following: newvar 2 -5 -4 Since observations are in the same variable Nov 21, 2020 · But because it's a daily date, the only format that makes sense is a daily date format. Stata makes it very simple to calculate the amount of time between two dates, because it internally represents each date as a number. Why is this? The short answer is that Excel rounds its datetime values to the nearest millisecond, while Stata doesn’t. c. In my export, they need to be named, exactly, "Street Line 1" and "Date of Birth," etc. com> Prev by Date: Re: st: xtreg fe - skewness and kurtosis in independent variables Next by Date: Re: st: xtreg fe - skewness and kurtosis in independent variables Previous by thread: st: xtreg fe - skewness and kurtosis in As mentioned earlier, subtracting dates in Stata involves adjusting numerical variables by subtracting the sample mean before calculating model coefficients. Converting dates from raw data using the "date ()" function The trick to inputting dates in Stata is to forget they are dates, and treat them as character strings, and then later convert them into a Stata date variable. Please read the Stata tag wiki to learn how to give a decent data example. See help functions for the basics, and see the Stata Functions Reference Manual for a complete list and full details of all the built-in functions. split can be useful when input to Stata is somehow misread as one string variable. You’ll learn the essential commands and functions that make this task straightforward, even if you’re new to Stata. Four of these reasons are listed below. Stata datetime/C is the same as datetime/c, except that it accounts for leap seconds and encodes If your dates are proper Stata daily dates, then you need to subtract one from the other, and convert to years, rounding down. Both double quotes (” and ”) and compound double quotes (‘” and ”’) are allowed; see [U] 18. ). 25 days per year is considered close enough. Indeed it is documented explicitly that Of your commands (assuming that you typed what you report; you should report what Stata typed in return) 25. Sep 25, 2020 · to get an overview I describe my data and afterward generates "_dif" variables expressing the difference between the operation date "op_date" and the hgb_0 and ferritin_0 _dates respectively. System date of survey and self-reported date of survey. Introduction Dates in any statistical software (Stata, R) are complicated. Number of observations (_N) was 0, now 1. In other words, total staff at the UN by year. The most Stata-ish way, from my personal view, to achieve this is by converting the string to a Stata time/date format, and years from this, as presented in the Jul 26, 2022 · This question is wide open without precise details on your data. If some parts of your composite variable are numeric characters that should be Description substr(s, tosub, pos) substitutes tosub into s at position pos. There is no need to check up on varying month length, 31, 30, 29 or 28 days. Dec 17, 2015 · Stata stores numeric dates as the number of elapsed days since 01 Jan 1960 for date () and the number of elapsed milliseconds since 01 Jan 1960 00:00:00:000 for clock (). We’ll begin by focusing on dates. First approach: extract the dates from the variables you have and then subtract the dates. Jul 1, 2024 · This function calculates the difference between two dates in days and can be applied to any date format in Stata. co. The model may have multiple thresholds, and you can either specify a known number of thresholds or let threshold find that number for you through the Bayesian information criterion (BIC), Akaike information criterion Feb 18, 2021 · I have dates in a CSV file saved from excel. com> Re: st: mean centering From: Aljar Meesters <aljar. The function birthday () tells you the birthday, as a Stata date, in a given year. generate double v1 = date ("22-6-2005", "DMY") generate double v2 Nov 16, 2022 · The problem I have panel data (or longitudinal data or cross-sectional time-series data). For example, if you know a subject’s birthday and the date of the beginning of the study, you can calculate how old they were when the study began by just subtracting. We discuss functions used to obtain Stata dates, including string-to-numeric conversions and conversions among different types of dates and times. Anyway, here are two: -summarize varname- will create scalars r (min) and r (max). Thanks to a member of this group I was able to create a variable that shows the order (so for person 1 there is record 1, record 2, etc. reulen@gmail. I have tried to generate a new variable displaying the change from 1995-2015 in (log) hours worked (HEMPE) using the following command: gen diffHEMPE = ln_HEMPE - ln_HEMPE [_n-20] which indeed displays the difference in changes between 1995 and 2015, but also displays Jul 25, 2015 · I have a file that contains multiple records for the same individual - each record is a different date on which the person was interviewed. When month, day, and year are in the form of a continuous string of numbers, such as Nov 13, 2024 · Learn how to subtract dates in Power BI using DAX and Power Query. 25. It will become apparent that the best solution to getting this is easily adapted to get the case of the minimum seen so far, the record when low values are hard to achieve (think of track events such Numerically encoded dates/times brought into Stata with import excel, import sas, or import spss will automatically be converted to Stata dates/datetimes. I wish to identify systematically the first (or last) occurrences of a particular condition in each panel with an indicator variable that is 1 when an observation is the first (or last) occurrence in a panel and 0 otherwise. r stands for return as in returned results, e stands for estimation as in estimation results, s stands for string, and, admittedly, this last acronym is weak, n stands for null. previousbirthday () and nextbirthday () return Stata dates for the previous and next birthday, respectively, relative to a given date. When the scale of a variable is not naturally interpretable, some will normalize (center and make standard deviation 1) to facilitate interpretation. For example, if I had four References: st: mean centering From: James Bernard <jamesstatalist@gmail. If your actual data include precise time of day, these will produce different results, so you need to think about which you want. Apr 18, 2019 · If you are running version 15. If not, run -ssc install dataex- to get it. Description mean produces estimates of means, along with standard errors. 7, and so on. e. Nov 18, 2020 · value [_n-1] refers to the preceding observation in the current sort order. com> Prev by Date: Re: st: Installation of ado-files in Stata Next by Date: Re: st: how to calculate a new variable subtracting from an original value a unit every time a condition is satisfied Previous by thread: st: Merging two plots in one coordination Prev by Date: st: Statalist advice: a summary Next by Date: RE: st: Interrater agreement: finding the problematic items Previous by thread: Re: st: Subtracting observations by group Next by thread: st: Statalist advice: a summary Index (es): Hello and thank you in advance I'm attempting to find the difference in days between events within different groups. If you need to subtract a portion (substring) from a string variable, you can use substr. Stata has a couple of different commands that produce tabular results. Format the result as a date to ensure it displays correctly. Aug 3, 2024 · In this article, we have demonstrated 6 ways of how to subtract date and time in Excel. This tutorial covers how SPSS treats Date-Time variables, and how to use the Date & Time Wizard to create and compute variables using dates and times. value [_n-1] and l. This solves one problem . g. The same can be said for datetimes to get milliseconds between two datetimes, weeks between week1 and week2, months, and so on. Numerically encoded dates/times brought into Stata with import excel, import sas, or import spss will automatically be converted to Stata dates/datetimes. Stata stores dates, times, and dates and times as integers such as 4,102, 0, 82, 4,227, and 1,479,735,745,213. In this entry, we discuss how to convert date and time values that you have imported from other packages to Stata dates. local assigns strings to local macro names (lclnames). The struggle I am having is that the dates are both in different formats. 2 SQL Reference, when you subtract 2 DATE datatypes, the result will be a Oct 17, 2021 · Objective I am converting a vector of strings of the following format "MM/DD/YYYY HH:MM:SS" to a Stata recognizable datetime using the clock() function. It works like this: You begin with the Re: st: how does one automatically calculate the age in years by subtracting the system date from the date of birth? Many thanks Rebecca for the very helpful and clear step by step explanation. In addition to the built-in date types above, such as %tc and %td, Stata provides a type you can define, denoted as %tb and called business dates and calendars. So far I have this code Prev by Date: st: How do I create a loop that calculates new variables by performing the simple mathematical function of subtracting one varlist on another varlist? Date of Birth Calculator: Pinpoint your date of birth by subtracting years from a current date. If your intent is to summarize data to understand them, you may need only these commands and not need collections. Therefore, Stata offers tools to turn these date strings into values that, while still displaying sensical data to humans, are encoded in a numeric format that Stata likes. Stata dates are numbers that can be formatted so that they look like the dates you are familiar with. Dear Stata-listers, I have the following dataset and I would like to subtract price by groups. Description These functions translate dates and times recorded as strings containing human readable form (HRF) to the desired Stata internal form (SIF). ) Nov 28, 2024 · And it also works with dates, not datetimes, so there will never be a fraction of a date, even if you use datediff_frac ()-. How to calculate the number of days, months, or years between two dates using the DATEIF function in Excel. value means the value of the first lag, i. The best way to give this information is to show a short example of your data, using the -dataex- command. com> Prev by Date: Re: st: mean centering Next by Date: Re: st: mean centering Previous by thread: Re: st: mean centering Next by thread: Re: st: mean centering Index (es): Date Thread We know that Stata has month () and year () functions available. The alternative to strings is numbers—0, 1, 2, 5. Jul 4, 2016 · One of the variables is the number of nationals from each state who are working as UN staff members. We do not expect users to add or subtract these incomprehensible numbers, but we make it possible to calculate Stata dates, relative to other dates. Functions that calculate durations, such as ages and other differences between datetimes Functions that calculate relative dates, or dates from other dates, such as the previous or next birthday or anniversary relative to a given date Functions that extract the different components from datetime values and variables a dates and datetimes. Oct 17, 2020 · I have 10 date variables in Stata for each ID in wide format, I want to check difference between each of the two consecutive dates and the difference between two consecutive dates shouldn't be less Jan 5, 2011 · Most software stores dates and times numerically, as durations from some sentinel date, but they differ on the sentinel date and on the units in which the duration is stored. , age in days given date of birth and date of observation, length of residence given date of immigration and date of observation) and add to and subtract from dates (e. Stata’s date and time values need to be formatted so they look like the dates and times we are familiar with. Stata stores dates as the number of days since 01jan1960, and datetimes as the number of milliseconds since 01jan1960 00:00:00. This process allows researchers to accurately identify trends, patterns, and associations between various factors and the risk of developing CKD. Description This entry provides a complete overview of Stata’s date and time values. 213. However, in some cases, the time value may seem to be behind in Stata. The two primary commands used for this are generate for creating new variables. j. The dates are written as the number of days since Jan 1, 1900. a. In this article, I’ll guide you through the process of calculating the difference between two dates in Stata. In Stata they are named things like "Street_Line_1" and "Date_of_Birth". “How many days have elapsed from Day A to Day B?” To address these Apr 11, 2024 · If your dates are proper Stata daily dates, then you need to subtract one from the other, and convert to years, rounding down. Assuming that people work with finance data is not recommended; assume no specialist knowledge beyond expertise in Stata. Apr 4, 2023 · Date format in Stata plays a crucial role when it comes to managing time-related data, which can be both essential and challenging. I would appreciate any help, Best, Marvin Description These functions translate dates and times recorded as strings containing human readable form (HRF) to the desired Stata internal form (SIF). com> Prev by Date: Re: st: xtreg fe - skewness and kurtosis in independent variables Next by Date: Re: st: xtreg fe - skewness and kurtosis in independent variables Previous by thread: st: xtreg fe - skewness and kurtosis in References: st: how do you subtract the value of one group from the value of another group? From: Ken Ning < [email protected]> Re: st: how do you subtract the value of one group from the value of another group? From: Ken Ning < [email protected]> Re: st: how do you subtract the value of one group from the value of another group? split can be useful when input to Stata is somehow misread as one string variable. I've had a lot of trouble figuring out how to do this in Stata. substr() may be used with text or binary strings. May 20, 2008 · This document is designed to help you conduct event studies using Stata. This is a handy way to make sure that your ordering involves multiple variables, but Stata will only perform the command on the first set of variables. SIF dates are convenient because you can subtract them to obtain time between dates, for example, datetime2 datetime1= milliseconds between datetime1 and datetime2 (divide by 1,000 to obtain seconds) date2 date1 For times, it is the number of milliseconds from the stroke of midnight on January 1, 1960. 1 Description The word string is shorthand for a string of characters. -egen min_varname = min (varname)- will create a new variable containing the minimum across all observations. Enter a start date and add or subtract any number of days, months, or years. Sep 13, 2018 · The variable bwght gives the birthweight of the baby (in ounces). We assume that you already have data with a date variable, which we call "date", and a company identifier, which we have called "company_id". net> RE: st: Time between 2 dates From: Nick Cox <n. You might have the following date data in your raw data file. By specifying the starting and ending dates, the function will return the exact number of days between the two dates. According to the Oracle 11. How do I convert these for use in Stata? In particular, I'm interested in extracting the 14. The first position of s is pos = 1. We saw how to work with the Data Editor in [GSW] 6 Using the Data Editor—this chapter shows how we would do this from the Command window. com> Prev by Date: Re: st: plotting empirical probability of being in military job at different ages Next by Date: RE: st: plotting empirical probability of being in military job at different ages Previous by thread: Re You can convert from one SIF type to another by using SIF-to-SIF conversion functions; see SIF-to-SIF conversion, below. The problem you are running into is that you want to replace strings with integers. Calculating New Variables Using Existing Variables in Stata The basic command to generate a new variable is gen newvar This will create a variable called, appropriately, newvar. Confirm that the date columns you are subtracting from each other are correctly identified. In this blog post, I will explore the importance of choosing the right date format to ensure accurate and efficient analysis using Stata software. When month, day, and year are in the form of a continuous string of numbers, such as 24. You solved this problem by making the integers strings. Dec 13, 2018 · Anyway, there are two approaches you can take to get what you want. one time period before as set by tsset or xtset. Thus _n == 1 identifies the first and _n == _N identifies the last observation in each group. Variables containing strings—called string variables—occur in data for a variety of reasons. cox@durham. If you need to prepare your data or want to try out the commands with our sample data, go to data preparation page. However, let's presume that you have yearly data with values for 2018 and Aug 1, 2018 · All of these manuals are included as PDFs in the Stata installation (since version 11) and are accessible from within Stata - for example, through the PDF Documentation section of Stata's Help menu. The dates in date2 are not repeated and are sorted within Id. 0 trying to store a variable value from one observation in a local macro (if the variable is a string) or in a scalar (if the variable is numeric). Note that you can only calculate variables from existing string variables. For dates stored as strings, the date () function does the conversion flawlessly. uk> Prev by Date: AW: st: AW: extract hours, minutes and seconds from date Next by Date: st: Doubt on the exexcution of a do file? Previous by thread: Re: st: extract hours, minutes and seconds from the difference, including the fractional part, from 1 to 2 in units of days, months, or years with the nonleap-year anniversary for 1 on 29feb the integer year, month, or day of with specifying year, month, or day the numeric day of the month corresponding to the number of days in the month of The import excel command will properly convert Microsoft Excel’s numerically encoded date and times to Stata’s numerically encoded date and times. All variable names need the underscores replaced by spaces. Nov 29, 2021 · I need to calculate the difference in days between two dates in R. You can convert from one SIF type to another by using SIF-to-SIF conversion functions; see SIF-to-SIF conversion, below. Commands include extracting different date components (such as day, month, year), converting from one date frequency to another (e. Here is the code that I've used, gen datetime = clock(dt, "MDY hms") format datetime %tc and here is the resulting data, where the original string is dt and is a Nov 28, 2017 · Often, researchers will subtract an industry value (often an annual average) from the firm value to try to compensate for inter-industry differences. The post also gives a few examples that are helpful in converting variables to proper STATA dates, which Dates, Times, & Stata Often data is imported into Stata with string format dates such as 10/09/1986 or 9oct1986. Description Most software packages store dates and times numerically as durations from some base date in spec-ified units, but they differ on the base date and the units. Hope this helps, Alex -----Original Message Apr 22, 2020 · I take it you are not really looking to create a binary variable (only zeros and ones) but rather just a numeric variable. Mar 1, 2024 · If your dates are proper Stata daily dates, then you need to subtract one from the other, and convert to years, rounding down. Stata date values record the number f days from 01jan1960. m. Discover how to extract the year from date variables in Stata with this easy-to-follow tutorial! Perfect for beginners and experienced users, this guide walks you through simple commands and Jul 14, 2016 · Dear all, I have a dataset which contain id number with the display format is %6. Oct 6, 2014 · Many Stata commands support the in qualifier, but here we need if and the syntax hinges crucially on the fact that under the aegis of by: observation number _n and number of observations _N are determined within the groups defined by by:. Hi everyone, I need to export my data out of Stata into a very finicky system that requires *exact* column headers. In conclusion, subtracting dates in Stata is an essential step in calculating age correctly in epidemiological studies. Does format mean Stata monthly date display format or something else? Are your monthly dates held in one variable or two? Are variables numeric or string. 0g. Feb 10, 2013 · Thanks a lot for the clarification. May 22, 2022 · I'm using Stata 16. Directly from help datetime you can see date2 - date1 = days between date1 and date2. If some parts of your composite variable are numeric characters that should be References: st: Subtracting in Variable by a Group From: Arya Eskamani <Arya. The date is formatted %td (daily). Stata orders the data according to varlist1 and varlist2, but the stata_cmd only acts upon the values in varlist1. Nov 23, 2017 · Hello, I am working on a panel-data and I wish to estimate the regressions on a period of 1995-2015 changes (long run trends). l. 213, and with dates and times such as 21nov2006 13:42:02. I also have another variable DateLeft: 19961001 This is also of long type and format Re: st: how does one automatically calculate the age in years by subtracting the system date from the date of birth? Jul 9, 2023 · I have been struggling to create a new variable that tells me the difference between two different dates. I want to calculate the total number of staff working at the UN across all countries for each year. From: Nick Cox <njcoxstata@gmail. And I would like to use substring command to create a new variable take the Dec 2, 2018 · Stata Help I haven&#39;t used STATA in long time and I haven&#39;t used date or time formatting in STATA Your question specifies neither sufficient detail about what you are starting with, nor what you want to get. If your dates are proper Stata daily dates, then you need to subtract one from the other, and convert to years, rounding down. Jul 11, 2024 · The correct way to handle dates in Stata is to convert them to a number measured in days elapsed since January 1, 1960. You can write these dates and times however you wish, such as 11/21/2006, November 21, 2006, and 1:42 p. Stata stores dates as the number of days elapsed since January 1, 1960 This means January 1, 1970, would be stored as 3653 ((365 × 10) + 3) We use display formats to display 3653 as January 1, 1970 Numeric dates Next by Date: st: shell stata invokes IC Stata instead of MP Previous by thread: st: how does one automatically calculate the age in years by subtracting the system date from the date of birth? Learn to work with dates and times in Stata. Re: st: how does one automatically calculate the age in years by subtracting the system date from the date of birth? How and why Stata stores dates Stata has dates and datetimes and they are stored differently. before 1999, after 1999) Extracts components of dates (year, day of week) The date () function can convert virtually any date format into elapsed dates, which is the format Stata uses to manipulate date information. To ensure accurate date calculations on Smartsheet, it is crucial to follow these steps Description These functions convert dates and times recorded as strings to Stata dates. The problem The resulting converted datetime is not equivalent to the input. Aug 2, 2024 · This article will show you how to add or subtract dates in Excel. Elapsed dates are calculated as the number of days from January 1, 1960. This format is useful for adding or subtracting dates and changing the format of date variables. The fact that dates are just numbers with a special class will allow us to perform operations like calculating the difference between two dates (e. Those regions are identified by a threshold variable being above or below a threshold value. Use dataex (ssc inst dataex). The date () function can convert virtually any date format into elapsed dates, which is the format Stata uses to manipulate date information. The authors of the guide can happily reveal that they have applied this a lot when working with ICD codes (classification system for diagnoses). Convert the dates to numbers by using the appropriate functions or formulas. If the string has embedded quotes, compound double quotes are needed. Description global assigns strings to specified global macro names (mnames). Moving from dates to Stata This module will show how to use date variables, date functions, and date display formats in Stata. 5 Double quotes. Giving us an example of your data would have helped. For example, a particular date could be coded as “4-5-2021”, or “5-4-2021” or “April 5, 2021” or “5APR2021”. Eskamani@assist-rx. Stata datetime/c values record the number of milliseconds f om 01jan1960 00:00:00. Sep 9, 2025 · Written and illustrated tutorials for the statistical software SPSS. Giving it a monthly date format is telling Stata these numbers are monthly dates! 1 January 1990 as a daily date is numerically 10958 (days from 1 January 1960) but as a monthly date it is 10958 months from January 1960 -- and that's a long way into the future. It discusses functions used to obtain Stata dates, including string-to-numeric conversions and conversions among different types of dates and times. 000. Moreover, the workbook as a template is available for free download here. Feb 24, 2021 · The first day of the next month is easy to find, and all you need to do then is subtract 1 to get the daily date of the last day of the current month. References: st: Time between 2 dates From: Laurie Molina <molinalaurie@gmail. References: st: extract hours, minutes and seconds from date From: raoul reulen <r. There are several ways to do this. Jones” are examples of strings. “Male” and “Female”, “yes” and “no”, and “R. įirst, we want to make sure we eliminate the repeated deaths from Patient 8. Travel Planning: Schedule trips by calculating exact durations between dates or find the day of the week for a future journey. , add one month or year). See [D] datetime for an introduction to Stata’s date and time features. These are two different data types, and in Stata you can't have a variable with two different data types. If you copy and paste into the Data Editor, say, under Windows by using the clipboard, but data are space-separated, what you regard as separate variables will be combined because the Data Editor expects comma- or tab-separated data. So YMD format. 1 Overview Stata has two matrix programming languages, one that might be called Stata’s older matrix language and another that is called Mata. But we cannot use them yet, since these two functions require that the input be in date format. While useful for a human eye, a computer can't glean much from data in this format. Date Prev Date Next Thread Prev Thread Next Date Index Thread Index Re: st: index number of an observation You can create the index first w/ a system variable, like this: gen index = _n The variable, index, should then uniquely identify each observation in your dataset and can then be used to reference a specific observation. I would like to have these two date saved in the same format. Jul 10, 2015 · Hello, I have two types of date variables in my data. When month, day, and year are in the form of a continuous string of numbers, such as Sep 10, 2020 · This page lists commands you may find useful when working with date variables in STATA. Mar 23, 2015 · The help for personage (SSC; you are asked to explain where programs come from) explains that it feeds on daily date variables, so feeding it anything else will just produce nonsense at best. The two dates are in different column and I just need to create another column named DAY_DIFFERENCE. We obtained a readable date by using the format command with %td for daily dates, %tc for datetime, and %tm for monthly. Follow-Ups: Re: st: how does one automatically calculate the age in years by subtracting the system date from the date of birth? From: Rebecca Pope <rebecca. It has a minimum abbreviation of g. This string variable contains time stamps. In addition to the multiplicity of possible formats it is also difficult to do calculations on these kinds of quantities e. uk> Prev by Date: RE: st: Herfindahl, segregation index Next by Date: st: Date from Intial visit Previous by thread: RE: st: Time between 2 dates Next by thread: st: Date from Intial Follow-Ups: Re: st: how does one automatically calculate the age in years by subtracting the system date from the date of birth? From: Rebecca Pope <rebecca. gen C=A-B if there is any easy & efficient method except my code, I would like to learn it. May 25, 2018 · Let me add something positive: to add, subtract, multiply, divide variables (in Stata not called columns), and so forth, use the operators + - * / and so forth. But it generates positive values when A is missing, even though I want it as negative. Stata translates dates, times, and datetimes into integer values that represent the data in a way that is useful for calculations like adding or subtracting dates to get elapsed time (but not really readable by a human). generate and replace This chapter shows the basics of creating and modifying variables in Stata. Each time stamp can be shortened to a date, which can be shortened to a year. 1 Overview A complete overview of Stata’s date and time capabilities can be found in [D] Datetime. In the stata exercise 2 of workshop 2018, it also shows me the code to track what’s the maximum time a unique CPSIDP shows up ( even after 1 year or 2 year later given the interview takes place two years before in December month ). Stata date and time values are durations (positive or ne ative) from 01jan1960. replace for replacing the values of an I don't understand this beyond it being about dates somehow. I have a file with 100+ columns. replace B = 0 if B==. How can I make my sytem date which is saved as double format (%tc) to long (%tdnn/dd/YY). That will give you fractions of months or weeks or years, or larger units, but never fractions of a day. What is the difference in average birthweight between smoking and non-smoking mothers? How do I do subtraction of means in St Mar 29, 2015 · I now realized that if we want STATA to deal with time we have to convert the string variable representing date into "STATA internal form" (count of seconds, days, months or years from 1960) first and then if necessary, change the format of "human readable form" (%td, %tm, etc. 3f. May 18, 2017 · First and Last Occurrences in Stata Asked 8 years, 3 months ago Modified 6 years, 2 months ago Viewed 3k times Nov 16, 2022 · The maximum value of a variable seen so far in a sequence is the “record” to date, that is, at least when high values are hard to achieve (think of field events such as jumping or throwing). See age2. 1 or a fully updated version 14. Stata’s Mata is the new one, and there is an uneasy relationship between the two. Smith” and “P. Dec 27, 2018 · Dear statalister, I am trying to merge to database, I would like to try using a concatenate of country and year, first is a string and the second a number. com> Re: st: Time between 2 dates From: David Kantor <kantor. In some fields, a rough average of 365. January 3, 2011 is stored […] Nov 9, 2016 · You should just be able to convert to a Stata date using daily(), and then subtract the two. Dec 12, 2018 · My variable DateBecame looks like this: 19550101 It is of long type and the format is %10. Perfect for data analysis. Knowing how to work with dates comes in particularly handy. Stata can work with dates such as 21nov2006, with times such as 13:42:02. Converting dates is easy to do. 2, -dataex- is already part of your official Stata installation. umvc nuljfcf rvjxntw klqfwhd gzpj xjtv aolv dvvsd zaiy bljuil