.TH datetime 3.SH NAMEdatetime \- convert between TAI labels and seconds.SH SYNTAX.B #include <datetime.h>void \fBdatetime_tai\fP(&\fIdt\fR,\fIt\fR);datetime_sec \fBdatetime_untai\fP(&\fIdt\fR);struct datetime \fIdt\fR;.brdatetime_sec \fIt\fR;.SH DESCRIPTIONInternational Atomic Time, TAI,is the fundamental unit for time measurements.TAI has one label for every second of real time,without complications such as leap seconds.Astruct datetimevariable,such as.IR dt ,stores a TAI label..I dt\fB.yearis the year number minus 1900;.I dt\fB.monis the month number, from 0 (January) through 11 (December);.I dt\fB.mdayis the day of the month, from 1 through 31;.I dt\fB.houris the hour, from 0 through 23;.I dt\fB.minis the minute, from 0 through 59;.I dt\fB.secis the second, from 0 through 59;.I dt\fB.wdayis the day of the week, from 0 (Sunday) through 6 (Saturday);.I dt\fB.ydayis the day of the year, from 0 through 365.The.B datetimelibrary supports more convenient TAI manipulation withthe datetime_sec type.A datetime_sec value, such as.IR t ,is an integer referring to the.IR t thsecond after the beginning of 1970 TAI.The first second of 1970 TAI was 0;the next second was 1;the last second of 1969 TAI was -1.The difference between two datetime_sec values is a numberof real-time seconds..B datetime_taiconverts a datetime_sec to a TAI label..B datetime_untaireads a TAI label(specifically.IR dt\fB.year ,.IR dt\fB.mon ,.IR dt\fB.mday ,.IR dt\fB.hour ,.IR dt\fB.min ,and.IR dt\fB.sec )and returns a datetime_sec..SH "SEE ALSO"now(3)