encoding/TAI

    Datetime is represented in, so called, external TAI64 format.
    => TAI64
    TAI stands for Temps Atomique International, the current international
    real time standard. Unlike UTC, it takes leap seconds into account,
    making it monotonous.
    => TAI

    You can convert UTC to TAI by adding the number of leap seconds.

    External TAI64 format is big-endian 64-bit number of TAI seconds passed
    since 1970-01-01, plus 1<<62. TAI64N format adds 32-bit big-endian
    number of nanoseconds (up to 999999999). TAI64NA adds another 32-big
    big-endian part of attoseconds.

    Shortest form *must* be used: if number of nanoseconds equals to zero,
    then use TAI64 format.

    Example representations:

    1970-01-01 00:00:00 TAI             | 18 4000000000000000
    1970-01-01 00:00:00 UTC             | 18 400000000000000A
    1969-12-31 23:59:59 TAI             | 18 3FFFFFFFFFFFFFFF
    1992-06-02 08:07:09 TAI             | 18 400000002A2B2C2D
    1992-06-02 08:06:43 UTC             | 18 400000002A2B2C2D
    1997-10-03 18:15:19 TAI             | 18 4000000034353637
    1997-10-03 18:14:48 UTC             | 18 4000000034353637
    2016-12-31 23:59:59 UTC             | 18 40000000586846A3
    2017-01-01 00:00:00 UTC             | 18 40000000586846A5
    2024-11-20 12:19:08 921772500ns UTC | 19 40000000673DD3E136F121D4