From double (%tc) to long (%tdnn/dd/YY) - Dates

[Marvin Aliaga]

Hello,

I have two types of date variables in my data. System date of survey and self-reported date of survey. I would like to have these two date saved in the same format. How can I make my sytem date which is saved as double format (%tc) to long (%tdnn/dd/YY).

I would appreciate any help,
Best,
Marvin

[Joe Canner]

Marvin,

This is not hard to do but you should be aware that %tc is for date/time variables, whereas %td is for date variables. Thus, you would be losing information (the time part) if you converted from date/time (%tc) to date (%td).

That said, if you want to convert a date/time variable to a date variable, use the dofc() function.

Regards,
Joe

[Nick Cox]

Joe gives good advice. In addition, note that double and long are storage types, not formats.

[Marvin Aliaga]

This is the information of my variables:

SystemDate double %tc Surveyed Date
DateToday long %tdnn/dd/YY Today's Date

I try:

gen SystemDateRC=dofc( SystemDate ) and it returns numbers. Can you please write the command.

I would greatly appreciate it

Best,
Marvin

[William Lisowski]

Having generated SystemDateRC, you also need to assign a format to it so that the numbers are displayed as the dates they represent. See help datetime for guidance, and for important background on working effectively with Stata dates and times. Your time spent mastering this will be well rewarded as you continue to use Stata.

[Nick Cox]

Marvin: the thread you started on 27 April raised essentially the same question.

[Marvin Aliaga]

Hi William, I tried gen SystemDateRC2 = dofc(SystemDateRC) But I guess I am doing something wrong. I would appreciate any help. On the other hand, when I command help sometimes a get only a partial explanation of the command. I guess I have also seen full explanations with examples. How can I access to those documents. BEst, Marvin

[Nick Cox]

William's #5 remains the advice to you.

Extraction of a daily date using dofc() should be followed by assigning some kind of %td display format.

There is nothing in your post to substantiate what you mean by "I guess I am doing something wrong".

The fuller documents behind the help you allude to are the Stata manuals, presumably.

Once again, I cross-refer you to the thread you started http://www.statalist.org/forums/foru...-hour-variable which refers to the same problem of extracting a daily date from a date-time variable.