datetime - convert between TAI labels and seconds
struct datetime dt;
International 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.
A struct datetime variable, such as dt, stores a TAI label.
dt.year is the year number minus 1900; dt.mon is the month
number, from 0 (January) through 11 (December); dt.mday is
the day of the month, from 1 through 31; dt.hour is the
hour, from 0 through 23; dt.min is the minute, from 0
through 59; dt.sec is the second, from 0 through 59; dt.wday
is the day of the week, from 0 (Sunday) through 6
(Saturday); dt.yday is the day of the year, from 0 through
The datetime library supports more convenient TAI
manipulation with the datetime_sec type. A datetime_sec
value, such as t, is an integer referring to the tth second
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 number of real-time seconds.
datetime_tai converts a datetime_sec to a TAI label.
datetime_untai reads a TAI label (specifically dt.year,
dt.mon, dt.mday, dt.hour, dt.min, and dt.sec) and returns a
Man(1) output converted with