Timestamp represents the value of units(seconds/milliseconds/microseconds/nanoseconds) elapsed
since UNIX epoch. The valid value range of Timestamp depends on it’s unit (all in UTC timezone):
The exact division of a timestamp value into a different unit:
quotient * from_scale + remainder == value * to_scale with
0 <= remainder < from_scale. quotient is the value floored in
to_unit; remainder == 0 iff the value is representable in to_unit.
Divides a value given in from_unit by to_unit, i.e. computes its
value in to_unit exactly (floor division). Returns None if the
quotient overflows i64.