Unix timestamp converter
Convert epoch timestamps to readable UTC dates — or parse dates back to seconds, milliseconds, microseconds and nanoseconds. Runs locally in your browser.
Unix Timestamp Converter
Convert Unix epoch timestamps into readable UTC dates, or parse common date strings back into epoch values. The tool auto-detects the direction by default: a numeric input becomes a date, while a date/time string becomes timestamp values.
What it supports
- Unix timestamps in seconds, milliseconds, microseconds or nanoseconds.
- Automatic unit detection by timestamp magnitude, with a manual unit override when you need it.
- ISO 8601 / RFC 3339 dates such as
2023-11-14T22:13:20Zor2023-11-15T00:13:20+02:00. - RFC 2822 email dates, slash dates, dotted dates and month-name dates through the shared date parser.
- UTC output including ISO 8601, RFC 2822, calendar components, day-of-year and ISO week.
- Date-to-timestamp output in all four units at once: seconds, milliseconds, microseconds and nanoseconds.
Modes
- auto — default. Numeric input is treated as a timestamp; non-numeric input is parsed as a date.
- to-date — force timestamp-to-date conversion.
- to-timestamp — force date-to-timestamp conversion.
When parsing a wall-clock date with no explicit timezone, the tool assumes UTC and sets assumed_utc: true in the output. If the input carries an offset, the instant is shifted to UTC before timestamps are returned.
Examples
1700000000→2023-11-14 22:13:20 UTC1700000000000→ auto-detected as milliseconds and converted to the same instant.2023-11-15T00:13:20+02:00→1700000000seconds.January 1, 1970→0seconds (assumed UTC midnight).
Everything runs locally in your browser or the gizza CLI; your dates never leave your device.
FAQ
How does it know whether my number is seconds or milliseconds?
By magnitude: a 10-digit value like 1700000000 reads as seconds, 13 digits as
milliseconds, 16 as microseconds, 19 as nanoseconds. That heuristic only breaks
for unusual instants (e.g. a millisecond timestamp from 1970 has few digits) —
in that case set the unit explicitly instead of leaving it on auto.
What timezone are converted dates shown in?
Output is always UTC — ISO 8601, RFC 2822, and the calendar breakdown all
describe the UTC instant. Going the other way, a date string with an offset like
+02:00 is shifted to UTC first; a wall-clock date with no timezone is assumed
to be UTC and the result is flagged with assumed_utc: true so you can tell.
Which date-string formats can it parse?
ISO 8601 / RFC 3339 (2023-11-14T22:13:20Z), RFC 2822 email dates, slash dates,
dotted dates, and month-name dates like January 1, 1970. If auto mode
misreads an ambiguous input, force the direction with to-date or
to-timestamp.
Why do I get four timestamps back for one date?
Date-to-timestamp conversion always returns the epoch value in all four units — seconds, milliseconds, microseconds, and nanoseconds — so you can paste the right one into whatever API you're working with without multiplying by hand.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool unix-timestamp-converter "1700000000 or 2023-11-14T22:13:20Z"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/unix-timestamp-converter/?value=1700000000%20or%202023-11-14T22%3A13%3A20Z&mode=auto&unit=autoMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.