TAI64, TAI64N, TAI64NA implementations for Python.
International Atomic Time (TAI) is the basic standard for measuring time. Universal Coordinated Time (UTC) is derived from TAI by adding or subtracting leap seconds according to the measured rotation speed of the Earth.
TAI64 is a family of formats for TAI times, first implemented in libtai. They have well known serialisations to bytes or hexadecimal.
| Format | Bytes | Resolution | Range |
|---|---|---|---|
| TAI64 | 8 | 1 second | 292 billion years |
| TAI64N | 12 | 1 nanosecond (10**-9 s) | 292 billion years |
| TAI64NA | 16 | 1 attosecond (10**-18 s) | 292 billion years |
The epoch for TAI64 is 1970-01-01 00:00:00 TAI, this is assigned the integer value 2**62.
>>> import tai64
>>> tai64.tai(sec=tai64.EPOCH)
tai64.tai(4611686018427387904)To deserialise a TAI64, TAI64N, or TAI64NA call the from_hex() or
unpack() class method.
>>> tai64.tai.from_hex('400000001dc03c40')
tai64.tai(4611686018926525504)
>>> tai64.tai.unpack(b'@\x00\x00\x00\x1d\xc0<@')
tai64.tai(4611686018926525504)To serialise call the hex() or pack() method
>>> tai64.tai(4611686018926525504).hex()
'400000001dc03c40'
>>> tai64.tai(4611686018926525504).pack()
b'@\x00\x00\x00\x1d\xc0<@'For nanosecond precision (9 decimal places) use tai64.tain(),
or for attosecond (18 decimal places) use tai64.taia().
>>> tai64.tain(4611686018926525504, nano=123).hex()
'400000001dc03c400000007b'
>>> tai64.taia(4611686018926525504, nano=1193046, atto=11259375).hex()
'400000001dc03c400012345600abcdef'
>>> tai64.taia.unpack(b'@\x00\x00\x00\x1d\xc0<@\x00\x124V\x00\xab\xcd\xef')
tai64.taia(4611686018926525504, 1193046, 11259375)tai() take raw unsigned int (current behaviour) or offset from epoch (time.time() behaviour)format() behaviourint() behaviour of TAI64N and TAI64NA__floor__() et alCLOCK_TAI