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Why Use the Online Converter Alongside Excel
- Instant verification — paste a timestamp and confirm your Excel formula is correct
- No formula needed — convert individual timestamps without opening Excel
- Handles edge cases — correctly handles timestamps near epoch boundaries
- Time zone support — convert to any time zone without manual offset calculation
- Millisecond detection — automatically detects whether a timestamp is in seconds or milliseconds
Use the Timestamp Converter for Excel at TechConverter.me to verify your formulas, convert individual timestamps quickly, and troubleshoot unexpected results in your spreadsheets.
Examples
Example 1: Basic Unix Timestamp to Excel Date Formula
The fundamental formula to convert a Unix timestamp (in seconds) in cell A1 to an Excel date:
=( A1 / 86400 ) + DATE(1970,1,1)How it works:
- 86400 = number of seconds in a day (60 × 60 × 24)
- Dividing by 86400 converts seconds to days
- DATE(1970,1,1) returns the Excel serial number for the Unix epoch start
- Adding them gives the Excel serial number for the timestamp's date
After entering the formula, format the cell as a date: press Ctrl+1, select Date, and choose your preferred format.
Example 2: Converting a Specific Timestamp
Converting Unix timestamp 1700000000 to a readable date:
Unix timestamp: 1700000000
Formula: =(1700000000/86400)+DATE(1970,1,1)
Result: November 14, 2023 (Excel serial number: 45244.6...)
Formatted as date: 14/11/2023
Formatted as datetime: 14/11/2023 22:13:20To display the time as well, format the cell as "dd/mm/yyyy hh:mm:ss" in the Format Cells dialog.
Example 3: Millisecond Timestamps (JavaScript / Modern APIs)
Many modern systems (JavaScript's Date.now(), most REST APIs) use millisecond timestamps. Divide by 86400000 instead:
Millisecond timestamp: 1700000000000
Formula: =(A1/86400000)+DATE(1970,1,1)
Example:
A1 = 1700000000000
Result = November 14, 2023 22:13:20To check whether your timestamp is in seconds or milliseconds: second timestamps are 10 digits (e.g., 1700000000), millisecond timestamps are 13 digits (e.g., 1700000000000).