Unix Timestamp Converter

A Unix timestamp is a single number that marks one exact moment in time. It counts the whole seconds since 00:00:00 UTC on January 1, 1970, the moment called the Unix epoch. The number is identical everywhere at the same instant, which is why databases, logs, and APIs store it instead of written dates.

Time zones only matter when the number becomes a readable date. Monday, November 2, 2026, 00:00:00 UTC is 1793577600, and that same number shows a different clock time in every time zone. Use the time zone converter to move a result from UTC into another zone.

The conversion is a single division, and the calculator shows its work every time. Here is the exact formula it runs.

timestamp_seconds = milliseconds_since_epoch ÷ 1000

timestamp_seconds is the Unix timestamp, the whole seconds since the epoch. milliseconds_since_epoch is the raw millisecond count the browser keeps for any date. The counting rule is simple. Every timestamp counts whole seconds since 1970-01-01 00:00:00 UTC, and leap seconds are not counted, so every day is exactly 86,400 seconds.

Take 1793577600 and convert it by hand. It is below 1,000,000,000,000, so it is seconds, not milliseconds. Multiply by 1,000 to get 1,793,577,600,000 milliseconds. Divide the seconds by 86,400 to get 20,759.0 days after the epoch, and counting 20,759 days forward from January 1, 1970 lands on November 2, 2026. The date engine reports the weekday. The final answer is Monday, November 2, 2026, 00:00:00 UTC.

1. Choose the Timestamp to date tab, enter a timestamp, and press Calculate.
2. Read the UTC time, your local time, the ISO 8601 form, and the weekday, plus the breakdown.
3. For the reverse, choose the Date to timestamp tab, pick a date and time, and select UTC or your local time.
4. Press Calculate to get the timestamp in seconds and milliseconds, or press Use current time anytime to convert the live timestamp.

The original definition counts seconds, so a current timestamp has 10 digits. JavaScript, Java, and most browser APIs count milliseconds, which is why the same moment can look like 1793577600 or 1793577600000. Mixing them up is the most common timestamp mistake.

The converter detects the unit by magnitude. Any value of 1,000,000,000,000 or more is treated as milliseconds, and anything smaller is seconds. The result always names the detected unit, so you can check it before you trust the date. For plain calendar math between two dates, the date calculator is the simpler tool.

A timestamp has no time zone inside it. 1793577600 is the same moment in London, Karachi, and Tokyo, and the cities only disagree on the wall clock. Convert to UTC first when you compare times from different places, then render into the zone you need.

Leap seconds are the one wrinkle. Real UTC occasionally inserts one, but Unix time skips it and keeps every day at exactly 86,400 seconds. Leap years are handled by the date math itself, since the browser calendar already knows every February 29. For a day-by-day count of a life, the age calculator runs the same calendar math.