Date to Unix Timestamp Converter

Converting Dates to Unix Timestamps

When working with time-based logic in code — setting expiry dates, scheduling future events, computing time differences — you often need to convert a human-readable date into a Unix timestamp. The Unix timestamp is the number of seconds since January 1, 1970 00:00:00 UTC, and it's the lingua franca of time in most databases and APIs.

Our converter takes a date and time input (with timezone), computes the Unix timestamp in both seconds and milliseconds, and shows the result in multiple formats. This is useful when: setting JWT expiration times (exp claim), configuring cookie max-age attributes, setting database row expiry in TTL-based systems, and creating test fixtures with specific timestamps.

Timezone handling is the trickiest part. Our converter asks for the timezone explicitly so there's no ambiguity — "midnight on February 19, 2024" is a different Unix timestamp in New York vs Tokyo. Always specify the timezone when the exact time matters for your use case.

Tips

• JavaScript: new Date("2024-02-19T00:00:00Z").getTime() / 1000 gives the Unix timestamp for a specific UTC date.
• PostgreSQL: EXTRACT(EPOCH FROM timestamp '2024-02-19 00:00:00+00') returns the Unix timestamp.
• JWT exp claim is in seconds, not milliseconds. Use Math.floor(Date.now() / 1000) + 3600 for 1 hour from now.
• When storing timestamps in databases, prefer UTC and store the Unix timestamp or an ISO 8601 string with timezone offset.