How to Convert a Unix Timestamp to a Date in Excel (and Back)
Every API response, server log and database export stores time as a count since 1 January 1970. Excel counts days since 1899. Nothing in Excel bridges the two, which is why that column of ten-digit numbers is still a column of ten-digit numbers.
Last updated: October 2026
| Timestamp | Date (UTC) | |
|---|---|---|
| 1772582400 | → | 2026-03-04 00:00:00 |
| 1772582400000 | → | 2026-03-04 00:00:00 |
Method 1 — a formula
- Seconds:
=A2/86400+25569, then format the result as a date (86,400 seconds in a day; 25569 is Excel's serial for 1 Jan 1970). - Milliseconds:
=A2/86400000+25569. - Get the unit wrong and the error is silent but enormous — seconds read as milliseconds land in 1970, milliseconds read as seconds land tens of thousands of years from now.
- The result is UTC. Shifting it to a local time means adding a fraction and remembering daylight saving yourself.
Method 2 — the 1-click way (Tellsheet)
Epoch Converter
Select the column and run Epoch Converter. It detects the unit — seconds, milliseconds, microseconds or nanoseconds — from the size of the numbers, and you can state the unit outright if you prefer. Pick a timezone and the result is shifted into it, daylight saving handled. The new column is written as a real Excel date, formatted yyyy-mm-dd hh:mm:ss, so it sorts, filters and charts properly — and only that column is formatted, so the rest of your table is untouched. Run it the other way to turn dates back into timestamps.
Which unit is my data in?
For a present-day date, a 10-digit number is seconds, 13 digits is milliseconds, 16 is microseconds and 19 is nanoseconds. JSON APIs and anything JavaScript-shaped usually mean milliseconds; Unix tools, Python's time.time() and most databases mean seconds.
Frequently asked questions
What's the formula?
=A2/86400+25569 for seconds; divide by 86,400,000 for milliseconds. Then format as a date.
Why did I get the year 50000?
Milliseconds treated as seconds. Auto-detection avoids this.
Are timezones handled?
Yes — timestamps are UTC, and the result is shifted into the zone you choose.
Can I go from dates back to timestamps?
Yes, in seconds, milliseconds, microseconds or nanoseconds.
Related Excel guides
Timestamps into dates, the right way round
Epoch Converter reads the unit, honours the timezone, and writes a real Excel date — both directions, one click.
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