Timestamp Converter

Unix Timestamp to Date Converter

The Tools Kit’s free Timestamp Converter turns a Unix timestamp into a readable date and turns a date back into epoch time. Paste an epoch value in seconds or milliseconds and see it as UTC, your local time and ISO 8601 at once, or pick a date and time to get the Unix timestamp in both seconds and milliseconds. Everything runs in your browser, with no sign-up.

It is built for the everyday jobs of reading a timestamp from a log line, an API response or a database row, and for generating an epoch value for a test, a query or a config file. It sits alongside the other unit and format tools in our conversion tools collection.

How to Use the Timestamp Converter

1. 1

   Enter a Unix timestamp

   Paste an epoch value in seconds (10 digits) or milliseconds (13 digits) into the first field. It is prefilled with the current time, and the Use Now button stamps the current second again at any point.

2. 2

   Read the converted date

   The same instant appears as a UTC date, your local time, and an ISO 8601 string, each with its own Copy button.

3. 3

   Convert a date to a timestamp

   Pick a date and time in the Date and Time field. The picker is read in your browser’s local time zone.

4. 4

   Copy seconds or milliseconds

   The epoch value is shown in both seconds and milliseconds, so you can copy whichever unit your code, database or API expects.

An invalid value shows an inline error message instead of a blank result, so a stray character or a typo is easy to spot.

What Is Unix Time (Epoch Time)?

Unix time, also called epoch time or POSIX time, counts the seconds since the Unix epoch: 00:00:00 UTC on Thursday, 1 January 1970. Timestamp 0 is that exact moment, 86400 is one day later, and negative numbers count backwards, so -86400 is 00:00:00 UTC on 31 December 1969. Leap seconds are not counted, which keeps every day exactly 86,400 seconds long.

Because a timestamp is one number with no time zone attached, it describes the same instant everywhere. That is why servers, databases and tokens store time this way: the exp, iat and nbf claims you see in a JWT decoder are Unix timestamps in seconds, and log files often stamp each line with one. To show the same moment as wall-clock time in several cities, use the time zone converter.

Seconds vs Milliseconds Timestamps

The most common timestamp mistake is mixing up units. Classic Unix tools, PHP’s time() and most SQL epoch functions work in seconds, giving 10-digit values for current dates such as 1735689600. JavaScript’s Date.now(), Java’s System.currentTimeMillis() and many web APIs use milliseconds, giving 13-digit values such as 1735689600000. Read in the wrong unit, a 2025 date lands in January 1970 or tens of thousands of years in the future.

This converter detects the unit from the length of the number: anything longer than 10 digits is treated as milliseconds, and anything shorter as seconds. Both of the values above therefore convert to the same instant. In the other direction, the milliseconds result is the seconds value multiplied by 1,000, and because the date picker works to the minute it always ends in 000.

UTC, Local Time and ISO 8601 Explained

Each timestamp is shown three ways. UTC is the zero-offset reference (browsers label it GMT, as in Wed, 01 Jan 2025 00:00:00 GMT). Local Time is the same instant on your device’s clock, including its offset and any daylight saving. ISO 8601 is the machine-friendly form, 2025-01-01T00:00:00.000Z, where the trailing Z marks UTC; it is the format most APIs and databases expect, and ISO strings sort chronologically when sorted as text, which helps when you tidy JSON payloads in the JSON formatter.

The date-to-timestamp picker has no time zone setting: the date and time you choose are read in your browser’s local time zone. If you are in UTC+5 and pick midnight on 1 January 2025, the result is 1735671600, five hours earlier than the UTC midnight value of 1735689600. Set your device to UTC, or adjust by your offset, when you need a UTC-based epoch value.

Common uses

• Reading the epoch time in a server log, error report or database row as a real date
• Checking whether a token’s exp timestamp has passed before debugging an expired session
• Generating a Unix timestamp for a test fixture, SQL query or API request
• Confirming when a scheduled job ran after setting it up with the cron expression generator
• Working out the gap between two dates in days with the days calculator once you have both as readable dates
• Pairing time-ordered IDs with real dates, for example when comparing UUID v7 values from the UUID generator with their creation times

Timestamp terms explained

Frequently Asked Questions