Using Date and Time Tools: Epoch, Time Zones, and Conversions

How to work with Unix timestamps, time zones, and date differences. With links to our epoch and timezone converters.

Published 2025-03-01. From the Vastorae team.

What is Unix time (epoch)?

Unix time is the number of seconds since 1 January 1970 00:00:00 UTC (the “epoch”). It’s used in programming, APIs, and databases because it’s a single number that’s easy to compare and store. Milliseconds since epoch are also common (e.g. in JavaScript).

To convert: enter the epoch value and see the human-readable date and time in UTC and your local time. Or enter a date and time to get the epoch value.

Time zones

Times are only meaningful with a time zone. UTC (Coordinated Universal Time) is the reference; other zones are offsets (e.g. EST = UTC−5). When you “convert” a time, you’re expressing the same moment in another zone.

Our timezone converter lets you enter a time in one zone and see it in others. Useful for scheduling across regions or checking “what time is it there?”.

Tools to use

Use the Epoch Converter to switch between Unix seconds (or milliseconds) and readable dates. Use the Timezone Converter to convert between time zones. Both run in your browser.

FAQ

Why do I get a different epoch than my friend?
Epoch is always in UTC. If you enter a local time, the tool must assume a zone; make sure you’ve selected the correct one.
What about leap seconds?
Most systems use “smoothed” time and ignore leap seconds for epoch. Our tool uses standard conversions.

Related tools

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