NAME

       tm - broken-down time

LIBRARY

       Standard C library (libc)

SYNOPSIS

       #include <time.h>

       struct tm {
           int         tm_sec;    /* Seconds          [0, 60] */
           int         tm_min;    /* Minutes          [0, 59] */
           int         tm_hour;   /* Hour             [0, 23] */
           int         tm_mday;   /* Day of the month [1, 31] */
           int         tm_mon;    /* Month            [0, 11]  (January = 0) */
           int         tm_year;   /* Year minus 1900 */
           int         tm_wday;   /* Day of the week  [0, 6]   (Sunday = 0) */
           int         tm_yday;   /* Day of the year  [0, 365] (Jan/01 = 0) */
           int         tm_isdst;  /* Daylight savings flag */

           long        tm_gmtoff; /* Seconds East of UTC */
           const char *tm_zone;   /* Timezone abbreviation */
       };

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       tm_gmtoff, tm_zone:
           Since glibc 2.20:
               _DEFAULT_SOURCE
           glibc 2.20 and earlier:
               _BSD_SOURCE

DESCRIPTION

       Describes time, broken down into distinct components.

       tm_isdst  describes  whether daylight saving time is in effect at the time described.  The
       value is positive if daylight saving time is in effect, zero if it is not, and negative if
       the information is not available.

       tm_gmtoff  is  the difference, in seconds, of the timezone represented by this broken-down
       time and UTC (this is the additive inverse of timezone(3)).

       tm_zone is the equivalent of tzname(3) for the timezone represented  by  this  broken-down
       time.

VERSIONS

       In C90, tm_sec could represent values in the range [0, 61], which could represent a double
       leap second.  UTC doesn't permit double leap seconds, so it was limited to 60 in C99.

STANDARDS

       C90 and later; POSIX.1-2001 and later.

       tm_gmtoff and tm_zone originate from 4.3BSD-Tahoe (where tm_zone is a char *).

NOTES

       tm_sec can represent a leap second with the value 60.

       timezone(3), as a variable, is an XSI extension: some systems  provide  the  V7-compatible
       timezone(3)  function.   The  tm_gmtoff  field  provides an alternative (with the opposite
       sign) for those systems.

       tm_zone points to static storage and may be overridden on subsequent calls to localtime(3)
       and similar functions (however, this never happens under glibc).

SEE ALSO

       ctime(3), strftime(3), strptime(3), time(7)