About EpochTimeConverter
EpochTimeConverter is a free timestamp tool for developers, analysts and support engineers. It converts between Unix time in any unit, standard date strings, platform epochs and timestamped IDs. It is built to be exact and to be clear about what it assumes.
How results are computed
Inputs are read as text and converted with JavaScript BigInt, so no step passes through a floating-point number. Instants are held as integer nanoseconds since 1970-01-01T00:00:00Z. Calendar fields use the proleptic Gregorian calendar with astronomical year numbering (year 0 is 1 BC).
Time-zone offsets come from the IANA tz database built into your browser, through the Intl API. Accuracy therefore depends on how up to date your browser is, and zone rules are only available inside the JavaScript Date range.
GPS and TAI conversions use a bundled leap-second table (IERS Bulletin C based, last leap second 2016-12-31 23:59:60 UTC). The table is asserted valid until 2026-12-28, and later instants are marked uncertain.
Feature status labels
Everything on this site runs in the browser (NATIVE browser APIs plus bundled TypeScript code). Nothing uses server processing, accounts or AI models. Where a format cannot represent an instant, the output says "Not representable" and explains why, instead of extrapolating.
Testing
The conversion engine has automated tests built from the product specification's fixtures, the RFC 9562 UUID test vectors, and thousands of randomised round trips checked against the browser's own Date.toISOString.