Unix Timestamp Converter

How to convert a Unix timestamp

1. Enter a signed integer and explicitly select Seconds or Milliseconds. Or fill in all seven UTC calendar fields.
2. Choose a display timezone. Search the supported IANA list or enter a supported identifier such as Europe/Stockholm.
3. Press the relevant Convert button, then copy individual fields or download the complete UTF-8 text result.

What is Unix time?

Unix timestamps count elapsed time from 1970-01-01T00:00:00Z. Negative values describe earlier instants. This tool does not represent leap seconds; calendar seconds must be 0–59.

Worked example

1704067200 seconds equals 2024-01-01T00:00:00.000Z and 1704067200000 milliseconds. Entering year 2024, month 1, day 1, and zero for the four time fields produces that same instant.

Europe/Stockholm displays 01:00 at UTC+01:00 for that winter instant. At 2024-07-01T00:00:00Z it displays 02:00 at UTC+02:00. Offsets are calculated for the date, not hard-coded per city.

Units, precision and negative timestamps

Seconds and milliseconds are never inferred from digit count. Millisecond input preserves all milliseconds. When there is a remainder, the seconds field is labelled whole seconds (rounded down). For example, -1 millisecond is 1969-12-31T23:59:59.999Z and its whole-seconds value is -1, not 0. Copy ISO or milliseconds to preserve subsecond precision.

Use current time captures one instant, fills both inputs and explicitly switches the timestamp unit to milliseconds. It does not tick or refresh automatically.

UTC entry and validation

Date entry always means UTC. Changing the display timezone does not reinterpret calendar fields. Impossible dates, such as 2023-02-29, are rejected instead of rolling into another month. Years 0001–0099 are handled explicitly, not mapped to the 1900s.

Accepted instants range from 0001-01-01T00:00:00.000Z through 9999-12-31T23:59:59.999Z. Integer parsing and bounds checks use BigInt before conversion to a safe numeric millisecond value. No clamping, exponent notation, decimals, separators, NaN, Infinity or trailing junk. Timestamp input is capped at 64 characters, UTC fields at four digits each, and timezone input at 128 characters.

Timezone and browser limitations

The initial display zone is your device's reported IANA timezone; UTC is always available. Readable local and selected-zone results include identifiers and date-aware offsets. Historical or future timezone data depends on the browser's timezone database; historical offsets may include seconds. This release does not resolve local calendar dates or ambiguous daylight-saving times into instants.

Changing inputs, units or the display zone clears the previous result. Clear offers in-memory Undo. Drafts disappear on refresh; no inputs are stored, logged, added to URLs or sent for remote conversion. If clipboard access fails, the requested text remains selectable for manual copying.