Hello! I have two date variables. The first one is the day of the interview and the other is a person's date of birth.
I am trying to find the number of days between the day of the interview and the birth date so that if I have dates of birth of multiple people, I can choose the one whose birthday is the closest to today (it is a way to do a random selection). For instance, if the person was born on 25/08/1992 and today is 27/08/1992, the output is supposed to be 2 days (meaning that we used only days and months). How can I do that in Limesurvey?

Thanks in advance!

I'm not sure I understand "using only months " but you can use the strtotime() function in an Equation type question to find the difference between dates.

Something like this will give the difference in days between the current date and a value entered in a Date type question:


Sample survey attached:

Do you want to replicate this selection procedure "Ask the person whose birthday anniversary is next"?
This would mean that the year is not relevant.

Joffm