ctime Functions & Types

This library contains types and functions to access the date and time.

• The types
  • a structure named tm which has the following fields:
    • int tm_sec - seconds after the minute (0-61)
    • int tm_min - minutes after the hour (0-59)
    • int tm_hour - hours since midnight (0-23)
    • int tm_mday - day of the month (1-31)
    • int tm_mon - months since January (0-11)
    • int tm_year - years since 1900
    • int tm_wday - days since Sunday (0-6)
    • int tm_yday - days since January 1 (0-365)
    • bool tm_isdst - is Daylight Savings Time
  • a type named time_t which stores an internal representation of the time.
• Some functions
  • int clock() - returns the processor time used by the program since the beginning of execution. clock()/CLOCKS_PER_SEC is a time in seconds.
  • time_t time(NULL) - returns an internal representation of the current time.
  • tm* localtime(const time_t*) - converts the internal time representation to a pointer to a tm structure.
• a sample program using the ctime library to obtain current date and time.
• another sample program using the ctime library to time a piece of code.