Unix Timestamp Converter | Epoch to Date & Timezone
Convert Unix timestamps (epoch seconds or milliseconds) to and from human-readable dates, with UTC, your local timezone, and any IANA timezone. Runs entirely in your browser — nothing is sent to a server.
Epoch → Date
Result
- UTC (ISO 8601)
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- Local timezone
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- Weekday
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- Selected timezone
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Date → Epoch
Result
- Epoch seconds
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- Epoch milliseconds
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Everything you enter is processed only in your browser and is never sent anywhere.
How to use
- Enter a Unix timestamp in the "Epoch → Date" field, or click "Use current time", to instantly see the UTC time, local time, and weekday.
- To check the time in a specific timezone, pick one from "Show in another timezone" and it appears alongside the other results.
- To go the other way, enter a date and time plus a reference timezone in "Date → Epoch" to get the epoch seconds and milliseconds.
How it works
Automatic unit detection
The tool detects seconds vs. milliseconds from the digit count of the number you enter (ignoring the sign). 10 digits or fewer is treated as seconds; 11 digits or more is treated as milliseconds. This is the threshold used by most similar tools — 10-digit seconds cover dates up to the year 5138, and 13 digits matches the length commonly used for millisecond timestamps today. You can override auto-detection by switching "Unit" to "Seconds" or "Milliseconds" explicitly. Microsecond and nanosecond notations (16 or 19 digits) are not auto-detected.
Timezone support
Besides UTC, you can view the date and time in your browser's local timezone or any timezone you choose. The timezone list comes from data built into your browser (the IANA time zone database), so no network request is made. The "Date → Epoch" section lets you pick UTC, local, or any timezone as the reference for the input date and time.
Daylight saving time boundaries
In regions that observe daylight saving time, the moment of transition creates a "nonexistent" hour (right after DST starts) and a "duplicated" hour (right after DST ends). This tool does not raise an error for times that fall in these boundary windows — it resolves them to one of the two possible interpretations. If your use case is sensitive to this, double-check times near a DST transition.
Supported range
Because of how JavaScript represents dates, values outside roughly the year -271821 to +275760 cannot be represented and will show an error. Dates before 1970-01-01 (negative epoch values) are fully supported.
FAQ
What is a Unix timestamp (epoch time)?
It's a way of representing a moment in time as the number of seconds (or milliseconds) elapsed since 1970-01-01T00:00:00 UTC. It's widely used in programs, databases, and log files.
How does the tool know whether my input is seconds or milliseconds?
It looks at how many digits the number has: 10 digits or fewer is treated as seconds, 11 or more as milliseconds. If that doesn't match what you intended, switch "Unit" to "Seconds" or "Milliseconds" to force it.
Can I convert dates before 1970 (negative timestamps)?
Yes. Dates before 1970-01-01 correspond to negative Unix timestamps, and you can enter and view negative values directly.
Does it handle daylight saving time correctly?
In most cases, yes. The exception is the exact moment of a DST transition — the nonexistent hour right after DST starts, and the duplicated hour right after it ends — where the tool resolves to one of the two possible interpretations rather than flagging an error.
Is anything I enter sent to a server?
No. All conversion happens entirely in your browser; nothing is sent over the network.
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