How to destring date variable (year month)?

[Ida Fallesen]

Hello,

I have a time series dataset with the following date variable format:

2000M09
2000M10
2000M11

And so on until 2015M09.

This variable is a string variable, which I would like to destring such that it can act as the date variable.

I have tried the functions date(date, "YM") and date(date, "YYYYMM") but it doesn't seem to work. My plan was then, once I have the numerical versions of my date variable, to format it to "monthly data".

Any ideas of how to destring this type of format (month year)?

Thank you very much in advance!

[Nick Cox]

Don't destring dates at all. The premise of destring here could only be that non-numeric text is irrelevant, so that you really have values such as 200009. But that isn't a date; it's an integer.

Also, as documented under help dates, date() is a function for producing daily dates, so it won't do what you want.

Further, you cannot change values by changing their display format.

As also documented under help dates, monthly() is a function for producing monthly dates, so it is what you want.

. di monthly("2000M09", "YM")
488

. set obs 1
obs was 0, now 1

. gen sdate = "2000M9"

. gen mdate = monthly(sdate, "YM")

. format mdate %tm

     +-----------------+
     |  sdate    mdate |
     |-----------------|
  1. | 2000M9   2000m9 |
     +-----------------+

In Stata 12+ you could use numdate (SSC) to do this.

N.B. Pretty much the same question was asked just a few days ago. http://www.statalist.org/forums/foru...a-monthly-date

Searching the archives is a really good idea!

[Ida Fallesen]

Thanks you very much! The numdate function worked perfectly!

[Nick Cox]

Good, but numdate is a command. Regardless of what is true in other software, functions and commands are disjoint in Stata.

[Davey Bakker]

Nick Cox is it possible to make dates like 2000m1d4 from integer values? Because that is what I have now... Examples, 19234, 16983 etc.

[Nick Cox]

As emphasised earlier in the thread, help dates leads to documentation. In turn that points to

help datetime display formats

Examples:

. di %tdCY!mn!dd 19234
 2012m8d29

. di %td 19234
29aug2012

So, if you had a daily date variable and you wanted it to display as in the first example, you would assign a format:

format mydate %tdCY!mn!dd

[Dania Arayssi]

Hi can you please help me?

I have a variable in state stored as string like this: " 2021-10-16" until 2022, and the days and month are not in order. I am trying to convert this variables to just 2021, 2022, by collapsing all these months/days into just year. Can you help me?

Thank you so much.
Dania

[Nick Cox]

#7 was double posted at https://www.statalist.org/forums/for...e-made-of-year Please follow there if interested.