Date to Unix Timestamp

Convert any calendar date into a standard Unix timestamp with this free date to unix timestamp tool. It runs in your browser and requires no signup. Just type your date and get the exact seconds since the epoch.

Understanding the date to unix timestamp mechanics

A Unix timestamp counts the seconds that have elapsed since January 1, 1970, at 00:00:00 UTC. That moment is the epoch. When you use an online date to unix timestamp converter, the browser parses your human-readable string into a standard Date object. It then calculates the mathematical difference between your target date and the epoch.

You will often see timestamps represented in milliseconds instead of seconds. JavaScript uses milliseconds natively, which adds three extra digits to the end of the value. This tool outputs standard POSIX seconds. If your specific application requires milliseconds, you simply multiply the result by one thousand. Most backend languages expect seconds by default.

When you need an online date to unix timestamp converter

Developers constantly translate human dates into machine time for API payloads. REST endpoints reject formatted strings and demand raw integers. You also hit this requirement writing database queries. Storing an integer takes less space and sorts faster than parsing strings on every read. It completely eliminates ambiguity around daylight saving time transitions.

System administrators use these values for log analysis. Grep and awk scripts filter massive text files by comparing raw epoch integers. You might also need this for cron jobs or cache expiration headers. Setting a max-age directive in HTTP requires a precise calculation of seconds from the current moment.

• Formatting payloads for third-party REST APIs.
• Writing efficient database queries for time-series data.
• Calculating exact cache expiration times for HTTP headers.
• Filtering application logs using standard command-line utilities.

Limits and edge cases for epoch time conversion

This tool handles Gregorian dates perfectly. Watch out for timezone offsets. The epoch is strictly UTC. Input a local time without an offset and the converter assumes UTC. This shifts your final integer by hours if you meant Eastern time. Always specify your exact timezone to prevent silent calculation errors.

You will also hit the Year 2038 problem if you work with 32-bit signed integers. The maximum value for a 32-bit integer is 2147483647. This corresponds to January 19, 2038, at 03:14:07 UTC. Any date beyond that point overflows and wraps around to a negative number on older systems. Modern 64-bit systems avoid this entirely, but legacy hardware still crashes.

• Always specify your timezone offset to prevent silent UTC shifts.
• Remember that 32-bit systems break after January 19, 2038.
• Leap seconds are ignored in standard POSIX time calculations.

How to use the date to unix timestamp converter

1. Type your target calendar date into the input field.
2. Select the correct timezone offset from the dropdown menu.
3. Choose whether you need seconds or milliseconds for your output.
4. Click the convert button to generate the integer value.
5. Copy the resulting timestamp directly to your clipboard.

Common reference dates and their Unix timestamps

Here is a quick reference for standard epoch milestones and common dates.

Frequently asked questions

Is this date to unix timestamp tool completely free?

Yes. You can convert as many dates as you need without paying anything. There are no hidden fees, premium tiers, or paywalls attached to this page.

How to convert date to unix timestamp in JavaScript?

If you need to know how to convert date to unix timestamp in JavaScript, create a new Date object with your target string. Call the getTime method to get milliseconds since the epoch. Divide the result by 1000 and use Math.floor to get standard seconds.

Why does my converted timestamp look wrong or off by a few hours?

You likely forgot to account for your local timezone offset. The converter assumes UTC by default. If you input a local time without adjusting for your timezone, the final integer will reflect the UTC equivalent, shifting the time by several hours.

Does this tool handle leap seconds?

No. Standard POSIX time ignores leap seconds. It assumes every day has exactly 86400 seconds. If you need strict astronomical time that accounts for the Earth slowing down, you need a specialized library, not a basic web converter.

Can I convert a timestamp back into a readable date?

This specific page only converts dates into timestamps. To reverse the process, you need a timestamp to date converter. You can find that tool in the same utilities section of this site.