EpochTimeConverter

Timestamp examples and boundaries

Boundary values that break software, with exact conversions. Select any example to load it into the converter.

Nowreading device clock…
Unix number in any unit, ISO 8601, RFC 2822, Excel serial, FILETIME, UUID, ULID or Snowflake.
Unit
IANA zone; type to search, e.g. Kolkata, Paris.
Precision and rounding
Same digits in other units
Other formats this number could be (4)
UTCUTC+00:00
2038-01-19 Tue
03:14:07
UTCUTC+00:00
2038-01-19 Tue
03:14:07

Read as Unix seconds (unit locked) high confidence

Precision check: exact vs JavaScript Number and Date
Exact (BigInt)
2 147 483 647 000 000 000 ns
Number(input)
2147483647 (no loss)
new Date(ms)
no loss
Unix epoch
Unix seconds2147483647Exact; fraction shown when present
Unix seconds (integer, floor)2147483647
Unix milliseconds2147483647000
Unix microseconds2147483647000000
Unix nanoseconds2147483647000000000
Unix seconds (hex)0x7FFFFFFF
Standard date formats
ISO 8601 (UTC)2038-01-19T03:14:07Z
RFC 3339 (UTC)2038-01-19T03:14:07+00:00
RFC 9557 (offset + zone)2038-01-19T03:14:07+00:00[UTC]
RFC 2822 (UTC)Tue, 19 Jan 2038 03:14:07 +0000
HTTP-date (IMF-fixdate)Tue, 19 Jan 2038 03:14:07 GMTAlways GMT; whole seconds
SQL TIMESTAMP (UTC)2038-01-19 03:14:07Microsecond precision max (PostgreSQL/MySQL)
SQL TIMESTAMP (UTC wall time)2038-01-19 03:14:07No zone stored: ambiguous without context
PostgreSQL timestamptz literal2038-01-19 03:14:07+00:00
ISO week date (UTC)2038-W03-2
Ordinal date (UTC)2038-019
Readable (UTC)Tuesday, 19 January 2038, 03:14:07 UTCCanonical English; not locale-dependent
Platform and system epochs
JavaScript new Date(ms)new Date(2147483647000)
Java InstantInstant.ofEpochSecond(2147483647L, 0L)Nanosecond precision
Python datetime (UTC)datetime(2038, 1, 19, 3, 14, 7, 0, tzinfo=timezone.utc)Microsecond precision
.NET DateTime ticks642830804470000000100-ns ticks since 0001-01-01 (DateTime.Ticks with Kind=Utc).
Windows FILETIME / LDAP137919572470000000100-ns intervals since 1601 UTC. Active Directory lastLogon, pwdLastSet, accountExpires.
Chrome / WebKit time13791957247000000Microseconds since 1601 UTC (Chrome history, cookies).
Apple Cocoa / Core Data1169176447NSDate timeIntervalSinceReferenceDate, Core Data, iOS/macOS plists.
Mac HFS+ seconds4230328447Classic Mac OS / HFS+ volume dates (seconds since 1904).
NTP seconds (era 0)4356472447NTP era 0 wraps on 2036-02-07; era numbers are not encoded in the 32-bit field.
Excel serial 1900 (UTC wall time) rounded50424.1348032407Days since 1900-01-00 with the Lotus 1-2-3 leap-year bug (serial 60 = fictitious 1900-02-29). No time zone.
Excel serial 1904 (UTC wall time) rounded48962.1348032407Older Mac Excel workbooks. Days since 1904-01-01. No time zone.
Julian Date rounded2465442.6348032407Days since noon UT, 24 Nov 4714 BC. Computed from UTC, so it ignores the UT1/TT distinction.
Modified Julian Date rounded65442.1348032407JD - 2400000.5. Computed from UTC.
GPS seconds1831518865After the leap-second table expiry (2026-12-28); a future leap second would change this value.
TAI (TAI-UTC = 37 s)2038-01-19T03:14:44 TAIBeyond the leap-second table expiry: uncertain
ID range bounds
Smallest UUIDv7 at this ms01f3ffff-fc18-7000-8000-000000000000Use as a range-query lower bound
Smallest ULID at this ms01YFZZZZ0R0000000000000000
Smallest Twitter / X Snowflake3601433561002934272
Smallest Discord Snowflake3050992291545088000
Smallest MongoDB ObjectId7fffffff0000000000000000
Settings and local data

Storage: checking…

Why boundaries matter

Most timestamp bugs appear at the edges: a signed 32-bit time_t overflows at 2038-01-19T03:14:07Z, JavaScript Date ends at year 275760, int64 nanoseconds end in 2262, and NTP era 0 wraps in 2036. Test fixtures that include these values catch overflow, sign and rounding errors before production does. Every example here converts exactly, and the converter shows a note when a value is beyond a common runtime's limit.

Examples to try

Using the examples as fixtures

Each example loads with its unit locked, so the output does not depend on auto-detection. Copy the ISO and Unix rows straight into your test cases. The Batch tab converts a whole list of fixtures at once, and the JSON export records the settings that produced them.

Questions

What happens in 2038?
Signed 32-bit Unix time reaches 2147483647 at 2038-01-19T03:14:07Z and wraps to -2147483648 (1901-12-13). Systems using 64-bit time_t are not affected.
Is epoch 0 midnight on 1 January 1970 everywhere?
It is 00:00:00 UTC. In New York it was 19:00 on 31 December 1969, and in India it was 05:30 on 1 January 1970.
What is the smallest negative 32-bit timestamp?
-2147483648, which is 1901-12-13T20:45:52Z.