How to compare two dates in dat?

Question

cmd/bat

Hello colleagues.
There is a task of comparison of two dates.
I get the first date like this:
set now=%date%
I get the second one like this:

FOR /F "tokens=* USEBACKQ" %%a IN (`net user /DOMAIN %username% ^| findstr /C:"Password expires"`) DO (set p=%%a)
set pass=%p:~29,-9%

Next, I need to compare these dates.
And if the difference between the dates is some n days, perform some actions.
Tell me, maybe someone knows how to work with dates.

Answer 1

Batniks do not know how to work with dates. All variables are strings.
Yes, it set /acan perform integer arithmetic, but the result is still a string.
You need to convert the dates to the number of days since the beginning of the epoch, and then they can be compared using standard means.
The easiest way is to use more advanced tools for these purposes that can work with dates, for example, powershel, JS, VBS - these scripts can be called from the batch file if desired.
But if you really want to, you can count the batch file. The calculation algorithm is on the wiki. The code can be pulled from here - https://www.robvanderwoude.com/files/datediff_nt.txt

Answer 2

see https://olegon.ru/showthread.php?t=16437 datemath.bat library