How to Convert Unix Timestamp in Excel and Google Sheets

Excel and Google Sheets use date serial numbers instead of Unix epoch seconds. These formulas convert Unix timestamps to spreadsheet dates with the correct epoch baseline.

The formula

In Excel, convert a Unix timestamp in seconds with:

= (A1 / 86400) + DATE(1970, 1, 1)

This divides the epoch seconds by the number of seconds per day and adds the Unix epoch start date.

Handling milliseconds timestamps

If your value is in milliseconds instead of seconds, divide by 86400000 first:

= (A1 / 86400000) + DATE(1970, 1, 1)

That converts the timestamp into days before adding the Excel epoch reference.

Google Sheets version

The same formula works in Google Sheets. If your sheet is in a local timezone, wrap the result with TO_DATE() and adjust the timezone if needed.

= TO_DATE((A1 / 86400) + DATE(1970, 1, 1))

Use a timezone offset or wrapper formula if your timestamp is not UTC.