easy way to add 1 month to a time_t in C/C++

Question

I have some code that uses the Oracle function add_months to increment a Date by X number of months.

I now need to re-implement the same logic in a C / C++ function.

Answer 1

Convert time_t to struct tm, add X to month, add months > 12 to years, convert back. tm.tm_mon is an int, adding 32000+ months shouldn't be a problem.

[edit] You might find that matching Oracle is tricky once you get to the harder cases, like adding 12 months to 29/02/2008. Both 01/03/2009 and 28/02/2008 are reasonable.