localtime() - transform timer data into timer structure in local time
#include <time.h>
struct tm * localtime (const time_t *clock)
The localtime(3) function takes as an argument a time value representing the time in seconds since the Epoch (00:00:00 UTC, January 1, 1970; see time(2)). It converts the time value pointed at by clock, and returns a pointer to a struct tm (described below) which contains the broken-out time information for the value after adjusting for the current time zone (and any other factors such as Daylight Saving Time). Time zone adjustments are performed as specified by the TZ environment variable (see tzset(3)). The function localtime(3) uses tzset(1) to initialize time conversion information if tzset(1) has not already been called by the process.
After filling in the tm structure, localtime(3) sets the tm_isdst element of tzname to a pointer to an ASCII string that's the time zone abbreviation to be used with localtime(3)'s return value.
External declarations as well as the tm structure definition are in the <time.h> include file. The tm structure includes at least the following fields:
| int | tm_sec; | seconds (0 - 60) |
| int | tm_min; | minutes (0 - 59) |
| int | tm_hour; | hours (0 - 23) |
| int | tm_mday; | day of month (1 - 31) |
| int | tm_mon; | month of year (0 - 11) |
| int | tm_year; | year - 1900 |
| int | tm_wday; | day of week (Sunday = 0) |
| int | tm_yday; | day of year (0 - 365) |
| int | tm_isdst; | is summer time in effect? |
The field tm_isdst is non-zero if summer time is in effect.
date(1)
asctime(3)
ctime(3)
gmtime(3)
mktime(3)
difftime(3)
getenv(3)
time(2)
tzset(3)