How do you get a previous date in C++?

[Alex T]

If you have the current date, how do you get the date 1 day or 2 days or 100 days back?

[weaknessforcats]

You use Julian days.

Pick a start date, like 1/1/2000 and calculate the number of days from then to your date. That will be the Julian day.

Then just subtract 100 days aand convert that result Julian date back to a calendar date.

[donbock]

Take a look at mktime (in time.h).