MKTIME(3C-POSIX)    RISC/os Reference Manual     MKTIME(3C-POSIX)



NAME
     mktime - convert broken-down time into calendar time

SYNOPSIS
     #include <time.h>

     timet mktime(timeptr)
     struct tm *timeptr;

DESCRIPTION
     mktime takes the contents of the tm structure pointed to by
     timeptr and converts it into calendar time (seconds since
     they epoch) of the type time_t.  mktime performs the oppo-
     site function of localtime and gmtime.

     The tm structure is defined in <time.h> and includes 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;      /* year (since 1900) */
          int     tm_wday;      /* days since Sunday [0-6] */
          int     tm_yday;      /* days since January 1 [0-365] */
          int     tm_isdst;     /* Daylight Savings Time flag */

     mktime manipulates the tm structure as follows:

     1. The contents of the structure are read; the fields
        tm_wday and tm_yday are ignored.

     2. The values of the other fields within the tm structure
        are not restricted to the values for tm.  For example,
        you can increment the tm_hour field to discover the
        calendar time one hour from now, even if this would make
        the value of tm_hour greater than 23.

     3. After the calculation is completed, the contents of the
        tm structure are reset to conform to the newly calculated
        calendar time.  The value of tm_day is not set until
        after the values of tm_mon and tm_year.

     4. The calendar time is returned.

     The value of tm_isdst is positive if Daylight Savings Time
     is in effect, zero if Daylight Savings Time is not in
     effect, and negative if the information is not available.

RETURN VALUES
     Upon successful completion, mktime returns the calendar time



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MKTIME(3C-POSIX)    RISC/os Reference Manual     MKTIME(3C-POSIX)



     corresponding to the contents of the tm structure indicated
     by timeptr.  Otherwise, mktime returns ((time_t)-1).

SEE ALSO
     clock(3), times(2).


















































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