The time.h facilities include:

• "struct tm" is a structure for storing time data.
• "tzname," an array that stores the time zone abbreviations
• "asctime" to convert a tm structure type to a char array
• "clock" to determine the relative time since the system was started
• "ctime" to convert a time_t type to a char array
• "difftime" to determine the difference between two times
• "gmtime" to determine Greenwich Mean Time
• "localtime" to determine the local time
• "mktime" to convert a tm structure to time_t type
• "strftime" to format time as a C string
• "time" to determine a number of seconds from a set time
• "tzset," internalizes the time zone to that of the application