CODEWITHSUNDEEP
datestata
CompSocialSciR
CompSocialSciR

Reputation: 593

Stata - generate date variable from days count

I want to generate a date variable starting from a count of the day and a starting date: I have a rolling cross-section with an integer variable that indicates the count of days since the survey was initially fielded. I also know this actual date. So, theoretically I should be able to generate a proper data variable, but I find no reference for this anywhere in the documentation.

Immagine I have one month of observations (in my case I have hundreds of observations for each day, but the problem is the same in this simplified case):

set obs 30
gen day=_n

I also know that day 1 is e.g. 12th of March 2015. How do I generate a daily date variable that ranges from 12th of March to the 11th of April?

Upvotes: 0

Views: 1036

Answers (1)

Richard Herron
Richard Herron

Reputation: 10102

Good comments to read the help file for dates/times. This is also my most-read help file, which suggests that it may not be that approachable for new users.

I use mdy() to determine the days since 1/1/1960, which I add to your day variable. There are may ways to do this, but this should get you started.

clear
set obs 30
gen day=_n

generate dayCalendar = (day - 1) + mdy(3, 12, 2015)
format dayCalendar %td

This gives you the following.

. list in 1/5

     +-----------------+
     | day   dayCale~r |
     |-----------------|
  1. |   1   12mar2015 |
  2. |   2   13mar2015 |
  3. |   3   14mar2015 |
  4. |   4   15mar2015 |
  5. |   5   16mar2015 |
     +-----------------+

Upvotes: 1

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