add seconds to a date

Question

I need to add seconds to a date. For example, if I have a date such as 2009127000000, I need to add the seconds to this date. Another example, add 50 seconds to 200912312359

Answer 1

The C date/time type time_t is implemented as the number of seconds since a certain date, so to add seconds to it you simply use normal arithmetic. If this is not what you are asking about please make your question clearer.