Time Functions (time.h)

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Time functions (time.h)

The following documentation discusses functions used either for reporting on time (elapsed, current, or compute time) or to perform calculations based on time.

- asctime
- clock
- ctime
- difftime
- gmtime
- localtime
- mktime
- strftime
- time

The header file, time.h, defines three types. clock_t and time_t are both used for representations of time particularly suitable for arithmetic. (In this implementation, quantities of type, clock_t, have the highest resolution possible on your machine, and quantities of type, time_t, resolve to seconds.) size_t is also defined if necessary for quantities representing sizes.

time.h also defines the structure, tm, for the traditional representation of Gregorian calendar time as a series of numbers, with the following fields.

tm_sec | Seconds.
tm_min | Minutes.
tm_hour | Hours.
tm_mday | Day.
tm_mon | Month.
tm_year | Year (since 1900).
tm_wday | Day of week: the number of days since Sunday.
tm_yday | Number of days elapsed since last January 1.
tm_isdst | Daylight Savings Time flag: positive means DST in effect, zero means DST not in effect, negative means no information about DST is available.

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