Combining separate day month year string variables to one dob variable

[steph aarsman]

Hello,

I have three variables (birth_day_child birth_month_child birth_year_child) which I need to convert to numeric variables, and combine to create a date of birth variable (dob).

I am not sure how to do it.

Thank you.

[Nick Cox]

If your variables are currently string, show us examples. Please read and act on FAQ Advice #12 to learn how.

If your variables are really numeric, you can proceed to

gen bdate = mdy(birth_month_child, birth_day_child,  birth_year_child)
format bdate %td

Resources you should be using:

help datetime


help mdy()


 mdy(M,D,Y)
       Description:  the e_d date (days since 01jan1960) corresponding to M, D, Y
       Domain M:     integers 1 to 12
       Domain D:     integers 1 to 31
       Domain Y:     integers 0100 to 9999 (but probably 1800 to 2100)
       Range:        %td dates 01jan0100 to 31dec9999 (integers -679,350 to 2,936,549) or missing

[Nick Cox]

destring does allow you to work on several variables at once. You could also do something like.

gen child_dob = mdy(real(month), real(day), real(year))

or

gen child_dob = daily (month + day + year, "MDY")