Generate Epoch Time in Excel

Use these Excel formulas to generate Unix timestamp (epoch) from any date/time or the current time. Includes seconds, milliseconds, timezone adjustments, and rounding.

Date/Time → Epoch (seconds)

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A1 contains a valid Excel date/time (UTC)

= (A1 - DATE(1970,1,1)) * 86400

Date/Time → Epoch (milliseconds)

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A1 contains a valid Excel date/time (UTC)

= (A1 - DATE(1970,1,1)) * 86400 * 1000

NOW() → Epoch (seconds)

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Generate current Unix time (seconds)

= (NOW() - DATE(1970,1,1)) * 86400

NOW() → Epoch (milliseconds)

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Generate current Unix time (milliseconds)

= (NOW() - DATE(1970,1,1)) * 86400 * 1000

Timezone & Rounding

Local time to UTC and whole‑second output

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If A1 is local time and your system is UTC+8, convert to UTC then to epoch (seconds)

= (A1 - (8/24) - DATE(1970,1,1)) * 86400

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Round down to whole seconds (avoid fractions)

= INT((A1 - DATE(1970,1,1)) * 86400)

Unix timestamp is defined in UTC. If your date/time is local, subtract your timezone offset in days (hours ÷ 24) before converting.
Use INT for whole seconds. For milliseconds, use ROUND or leave as decimal times 1000.
Format input cells as Date/Time; result cells can be General or Number.
Tip: If your workbook uses the 1904 date system (Excel for Mac option), turn it off for consistency, or adjust by +1462 days before converting.

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