Chapter 42 Time and Time Zones

Time representations

xtime is signed int64 UTC milliseconds since 0001-01-01 CE. Civil years are ..., -2, -1, 1, 2, ...; there is no year zero. xdatetime.Millisecond is 0 through 999.

xrtTimer() reads the high-resolution monotonic timer in double seconds. Its origin has no calendar meaning; subtract two readings to measure elapsed time. Waits and sleeps accept relative milliseconds.

double Start = xrtTimer();
xrtSleep(10);
double ElapsedSeconds = xrtTimer() - Start;

xrtDateDiff returns an integer difference in the requested dimension. Fixed units truncate elapsed milliseconds toward zero; years and months use continuous calendar indices. Calendar addition clamps month ends and skips the nonexistent year zero.

Signed Unix 32-bit seconds, 64-bit seconds and 64-bit milliseconds have checked bidirectional conversions. Negative second conversions floor; failed conversions leave outputs unchanged. Fixed-offset splitting covers the full int64 domain, while native local zones and text protocols have narrower ranges. %f is three millisecond digits.

See the Time API and Wait API for complete contracts.