Tool

Date to Epoch Converter

Choose a calendar date, time, and timezone, then convert that local wall-clock time to Unix seconds and milliseconds. Useful for APIs, cron jobs, logs, database rows, and tests.

Convert a human date to Unix time

This page handles the reverse conversion: start with a date, a clock time, and the timezone where that time should be interpreted. The result is a single Unix timestamp that represents the same moment everywhere.

When to use seconds or milliseconds

Use seconds for most backend languages, databases, and command-line tools. Use milliseconds for JavaScript Date, browser APIs, analytics events, and systems that need sub-second precision.

  • Unix seconds are usually 10 digits for modern dates
  • Unix milliseconds are usually 13 digits for modern dates
  • ISO 8601 is best when you want a readable string with explicit UTC output
  • UTC strings are useful for HTTP headers, logs, and quick human checks

Timezone handling

A local date such as 2026-05-14 08:00 means different instants in Los Angeles, New York, London, or Tokyo. Selecting the timezone before conversion avoids off-by-hours mistakes and handles daylight saving time rules through the browser's Intl API.