Epoch Converter
Convert Unix timestamps to dates and back.
How to use Epoch Converter
Convert Unix epoch timestamps to human dates and back. Supports seconds and milliseconds.
Open Epoch Converter on toolpermarket and enter your values in the fields below.
In the Timestamp field, enter either a Unix epoch in seconds or a human date-time. Pick the direction — epoch to date, or date to epoch.
In the Timezone field, choose UTC or your local zone for the readable output. Always note the zone; 1700000000 UTC and local can differ by hours.
Press Convert to compute the result. The output appears immediately below the form. You can change any input and run it again to compare results.
Read the result and use it as needed. If the number looks off, re-check your inputs and run it again — the math is deterministic, so the same entries always return the same answer.
Worked example. Converting epoch 1700000000 returns 2023-11-14 22:13:20 UTC, and the reverse turns that date back into the same epoch.
Tips for accurate results.
Confirm seconds vs milliseconds — 13-digit values are milliseconds.
Lock the timezone before comparing logs from two servers.
Copy the ISO form when interoperability matters.
When to use Epoch Converter. Reading epoch timestamps from API or database dumps. Generating epoch values to seed test data. Reconciling logs recorded in different zones.
When you actually reach for this
- You have a Unix timestamp from a log or API and need the human-readable date in your timezone.
- You are storing or comparing times and must convert between epoch seconds and a date object correctly.
Where this tool stops being accurate
- Know your unit: many systems use seconds, others milliseconds (JavaScript Date.now()), and mixing them offsets the date by 1000x.
- Timezone and UTC offset are easy to forget; the same epoch shows different local times depending on where you view it.
Frequently asked questions
Why is my converted time off by hours?
Almost always a timezone mismatch. Unix epoch counts seconds since 1970-01-01 in UTC, so the same number maps to different local clocks around the world. Set the display zone explicitly and, when sharing, prefer the UTC value or a full ISO string with offset so nobody has to guess.
Seconds or milliseconds — which is right?
A ten-digit number like 1700000000 is seconds; a thirteen-digit number like 1700000000000 is milliseconds. If your result lands in the year 50,000 you used the wrong unit. Switch the input interpretation and it will correct immediately.
Does leap seconds affect the result?
For everyday conversion, no. The POSIX epoch ignores leap seconds and treats every day as exactly 86400 seconds, which is what almost all systems actually store. Only specialized astronomical or timing work needs to account for the occasional inserted leap second.
Why is my converted date 1970 or wildly off?
You likely swapped seconds and milliseconds (or vice versa). Check whether the source uses 10-digit seconds or 13-digit ms and convert accordingly.
Does epoch account for leap seconds and DST?
Unix time ignores leap seconds and is UTC-based; local DST only affects how you display it, not the stored value.