Timestamp interrogation desk · one number, four possible units
A number is not an instant until its unit is known.
Unix time is timezone-free arithmetic. Civil dates are policy. This converter keeps the unit gate, sub-millisecond remainder, UTC instant, and named-zone display on separate evidence rails.
54,202 CE
unlikely API payload
2024-03-09
common browser clock
1970-01-20
database precision
1970-01-01
system trace precision
Magnitude can suggest a unit; only the producing contract can prove it.
Signed epoch-zero axis
before 1970
1970-01-01T00:00:00Z
+ 16m 40s
current observation
same signed scale
One-instant ledger
Wall-clock customs
An offset turns a wall clock into an instant.
2026-11-01T01:30AMBIGUOUSDST overlap in some zones2026-03-08T02:30MAY NOT EXISTDST gap in some zones2026-08-03T10:00ZEXPLICITUTC instant2026-08-03T10:00+08:00EXPLICITsame instant as 02:00ZPrecision bridge
integer evidence
digits preserved
millisecond display
civil-time projection
Incident board
milliseconds divided twice
seconds treated as milliseconds or the inverse
unit contract missing at API boundary
timezone-less ISO parsed by environment
nanoseconds rounded into Date
Leap-second boundary
POSIX seconds are not an astronomical clock.
Unix/POSIX time does not number leap seconds as distinct instants. Use a timescale-aware system when UTC leap events or astronomical time are part of the requirement.