in msgpak https://github.com/msgpack/msgpack/blob/master/spec.md

Timestamp extension type
Timestamp extension type is assigned to extension type -1. It defines 3 formats: 32-bit format, 64-bit format, and 96-bit format.

timestamp 32 stores the number of seconds that have elapsed since 1970-01-01 00:00:00 UTC
in an 32-bit unsigned integer:
+--------+--------+--------+--------+--------+--------+
| 0xd6 | -1 | seconds in 32-bit unsigned int |
+--------+--------+--------+--------+--------+--------+

timestamp 64 stores the number of seconds and nanoseconds that have elapsed since 1970-01-01 00:00:00 UTC
in 32-bit unsigned integers:
+--------+--------+--------+--------+--------+------|-+--------+--------+--------+--------+
| 0xd7 | -1 | nanosec. in 30-bit unsigned int | seconds in 34-bit unsigned int |
+--------+--------+--------+--------+--------+------^-+--------+--------+--------+--------+

timestamp 96 stores the number of seconds and nanoseconds that have elapsed since 1970-01-01 00:00:00 UTC
in 64-bit signed integer and 32-bit unsigned integer:
+--------+--------+--------+--------+--------+--------+--------+
| 0xc7 | 12 | -1 |nanoseconds in 32-bit unsigned int |
+--------+--------+--------+--------+--------+--------+--------+
+--------+--------+--------+--------+--------+--------+--------+--------+
seconds in 64-bit signed int |
+--------+--------+--------+--------+--------+--------+--------+--------+

but in the tinylib/msgp, time.Time Marash func is not follow the spec.

func putUnix(b []byte, sec int64, nsec int32) {
	b[0] = byte(sec >> 56)
	b[1] = byte(sec >> 48)
	b[2] = byte(sec >> 40)
	b[3] = byte(sec >> 32)
	b[4] = byte(sec >> 24)
	b[5] = byte(sec >> 16)
	b[6] = byte(sec >> 8)
	b[7] = byte(sec)
	b[8] = byte(nsec >> 24)
	b[9] = byte(nsec >> 16)
	b[10] = byte(nsec >> 8)
	b[11] = byte(nsec)
}