Free Unix Timestamp Converter - Epoch Time to Date & Date to Timestamp Online

A Yes, the tool shows a live clock displaying the current Unix epoch time in seconds and milliseconds. It updates every second automatically. You'll see it right at the top of the page, ticking away in real time. This is handy for testing code snippets or verifying timestamps without opening a terminal. Just refresh the page if you need to reset it.

A Yes, this tool handles both. Paste a 10-digit number and it treats it as seconds. A 13-digit number gets read as milliseconds automatically. For example, 1700000000 (seconds) converts to November 14, 2023, while 1700000000123 (milliseconds) gives you a precise time with milliseconds shown. If you're working with timestamps from JavaScript's Date.now(), those are milliseconds. Database timestamps from MySQL or PostgreSQL usually come in seconds. The tool figures out the format on its own.

A Leap seconds are real—27 have been added since 1972. But Unix timestamps don't account for them directly. They treat each day as exactly 86,400 seconds long. When a leap second happens, the system typically repeats or smears the last second. So if you convert a timestamp that falls during a leap second event, you might see a 1-second discrepancy compared to atomic clock time. For most applications, this doesn't matter. GPS satellites need higher precision, but your web logs won't care.

A The old 32-bit Unix timestamp limit hits on January 19, 2038—that's the Y2K for Unix. Modern systems use 64-bit timestamps, which won't overflow for billions of years. This tool runs on 64-bit under the hood, so 2038 isn't an issue here. But if you're working with legacy embedded systems or old databases that still use 32-bit integers, you'll start seeing errors around 03:14:07 UTC on that date. Test a future timestamp like 2147483648 and watch it convert fine.

A That's the Unix epoch's birthday—January 1, 1970 at midnight UTC. If you see December 31, 1969, it means your timestamp is -1 or close to zero. You likely typed a date string the tool couldn't parse, or you pasted a timestamp in seconds when it should be milliseconds. Try adding three zeros to the end of a 10-digit number. A timestamp like 1700000000 is seconds; 1700000000000 is milliseconds. Big difference in what date you'll get.

A The tool strips surrounding whitespace automatically, but embedded junk gets flagged. Paste something like "1700000000abc" and you'll get an invalid date error, not a partial conversion. Paste "1700000000" with a trailing space and it converts fine. For timestamps with timezone offsets like "1700000000+0200", the tool ignores the offset and treats the base number as UTC. If you're copying from logs that include brackets or quotes, clean those out first—the tool won't guess what you meant. A quick habit: highlight just the digits before pasting.

A The Unix timestamp always counts seconds from January 1, 1970, at midnight UTC. This tool displays results in UTC by default. If you're in Tokyo (UTC+9), a timestamp that reads 15:00 UTC shows as midnight the next day locally. Your 09:00 AM local time becomes 00:00 UTC—that's the same moment, just shifted. Check the tool's timezone dropdown or mentally add your offset. For a quick sanity check, convert 1700000000 and see what time it shows for you. Most confusion clears up once you realize the number itself is timezone-agnostic.

A A Unix timestamp is a single number counting seconds since January 1, 1970 UTC. ISO 8601 is a text string like '2025-02-23T14:30:00Z'. The timestamp works well for math—subtract two values and you get exact durations. But humans can't read it without conversion. Say you're tracking a project deadline: storing '2025-12-31' in a database is clear, but comparing it against another date requires parsing logic. This converter lets you jump between both worlds. For academic citations or API payloads, ISO 8601 often wins for readability. For performance metrics and logs, timestamps are lighter and faster. Pick based on who consumes the data.

A This specific converter handles one value at a time to keep your browser running fast. If you're debugging thousands of entries from an Apache or Nginx error log, paste them into a script instead. You can write a quick one-liner in Python using the datetime module. Just loop through your log file and print the readable dates. For checking a single suspicious log entry right now, pasting it here takes two seconds.

A Yes, negative numbers represent seconds before the 1970 epoch. Typing -86400 gives you December 31, 1969. You can go back centuries this way. Try inputting -2208988800 to see January 1, 1900. It's useful for genealogy research and old databases.