caltime 3 user commands djbwares caltime_tai convert calendar dates and times #include <caltime.h> #include <tai.h> void \fBcaltime_tai\fP(&\fIct\fR,&\fIt\fR); void \fBcaltime_utc\fP(&\fIct\fR,&\fIt\fR,&\fIweekday\fR,&\fIyearday\fR); struct caltime \fIct\fR; struct tai \fIt\fR; int *\fIweekday\fR; int *\fIyearday\fR; caltime_tai reads a date, time, and UTC offset from ct. It puts the corresponding TAI64 label into t. caltime_utc reads a TAI64 label from t. It puts the corresponding date and time into ct, with UTC offset 0. caltime_utc fills in weekday and yearday the same way as caldate_frommjd. The sequence of TAI64 labels has been determined for the next few hundred billion years. The same is not true, however, for calendar dates and times. New leap seconds are added every year or two, as discussed in leapsecs3; and the Gregorian calendar will change in a few thousand years, as discussed in caldate_mjd3. This means that caltime_tai and caltime_utc are not useful for dates far in the future. caldate_mjd3 caltime3 tai3 leapsecs3 Original code and documentation by Daniel J. Bernstein. Converted to DocBook XML by Jonathan de Boyne Pollard.