If the time (0) operator is seconds ... then what is minutes and hours or even days maybe?

Question

is days even possible?

Answer 1

Yes, how many seconds are in a minute, hour etc..
Anyway see http://www.cplusplus.com/reference/ctime/time/

Particularly: Although libraries may use a different representation of time: Portable programs should not use the value returned by this function directly, but always rely on calls to other elements of the standard library to translate them to portable types (such as localtime, gmtime or difftime).