Docify

Unix timestamp converter

Convert epoch seconds or milliseconds to a date, or parse an ISO 8601 string. Nothing is uploaded.

Docify's Unix timestamp converter maps POSIX time — seconds since 1970-01-01T00:00:00Z, ignoring leap seconds — with JavaScript Date. Seconds use new Date(n * 1000); milliseconds use new Date(n). Date strings go through Date.parse. toISOString() is UTC. Local display uses the browser time zone. Nothing is uploaded.

Timestamp to date
Date string to timestamp

How it works

  1. Convert and Now are buttons, not as-you-type.
  2. Timestamp → date reads a decimal number. Seconds call new Date(n * 1000). Milliseconds call new Date(n). The unit is not inferred from digit count.
  3. Date string → timestamp uses Date.parse. Unix seconds are Math.floor(ms / 1000). Milliseconds are getTime().
  4. Now uses Date.now() (or new Date().toISOString() on the date card). Outputs are toISOString() (UTC), toUTCString(), and toLocaleString() in the browser zone. Leap seconds, TAI, microseconds, and JWT claims are out of scope.

FAQ

Does this converter upload anything?
No. Conversion runs in your browser with JavaScript Date. The page does not send the number or date string to a server.
Are Unix timestamps seconds or milliseconds?
POSIX / Unix time is seconds since 1970-01-01T00:00:00Z, ignoring leap seconds. JavaScript Date.now() and getTime() are milliseconds. This page does not auto-detect the unit: pick Seconds (new Date(n * 1000)) or Milliseconds (new Date(n)).
Is the result UTC or my local time?
toISOString() is always UTC with a Z suffix. toUTCString() is the UTC HTTP-date style string. The Local row uses toLocaleString() in the browser time zone from Intl.DateTimeFormat().resolvedOptions().timeZone. There is no IANA zone picker and no NTP clock.
Which date strings can I convert?
Date.parse only. ISO 8601 with a Z or numeric offset (for example 2026-08-19T22:48:00Z) is the reliable form. A date-only YYYY-MM-DD is UTC midnight in ES5. Locale phrases are engine-specific. This is not TAI, not a leap-second table, and not a JWT validator.

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