Timestamp Converter

Convert between Unix timestamps and local date-time; seconds and milliseconds supported.

What this tool does

Converts Unix timestamps — seconds or milliseconds since 1970-01-01 00:00:00 UTC — to human-readable dates and back, and can grab the current time with one click. Conversion is local, and results are shown in your browser's time zone alongside UTC.

Typical use cases

Translating 1735689600 in a log into “what time was that?”; checking what moment an API's expire_time actually means; verifying a database created_at against business expectations; turning “next Monday at midnight” into a timestamp for a cron job. In cross-timezone collaboration, a timestamp is the only unambiguous way to communicate — 1735689600 is the same instant everywhere on Earth.

Caveats

The biggest trap is seconds vs. milliseconds: JavaScript's Date.now() returns milliseconds while most backends return seconds — a 1000× mix-up produces dates in 1970 or the year 51000. This tool supports both; check your source's unit first. Also worth knowing: 32-bit signed integers storing second timestamps overflow on 19 January 2038 (the “Year 2038 problem”), which matters when maintaining older systems.