Browser tool Runs locally
Unix Timestamp Converter
Convert Unix timestamps to dates and dates to timestamps. Runs locally in your browser.
Timestamp
Unit
Display in
Converted date and time
Converted date and time will appear here.
What is a Unix timestamp?
A Unix timestamp (also called epoch time or POSIX time) counts the number of seconds that have elapsed since 1970-01-01 00:00:00 UTC, ignoring leap seconds. Because it's a single number rather than a formatted string, it's the format of choice for databases, APIs, log files, and any system that needs to store or compare points in time without worrying about timezones or locale-specific date formats.
How to convert a timestamp to a date
- Select Timestamp → Date.
- Enter the timestamp and choose Seconds or Milliseconds.
- Choose UTC or Local.
- Click Convert Timestamp.
How to convert a date to a timestamp
- Select Date → Timestamp.
- Pick the date and time, and indicate whether it's UTC or local.
- Click Convert Timestamp to get the epoch value in both seconds and milliseconds.
Practical examples
- Debugging an API response that returns
created_at: 1735689600- paste it in to see the actual date instantly. - Setting a JWT
expclaim to a specific expiry time, e.g. "one hour from now." - Comparing two log entries to figure out exactly how many seconds apart they occurred.
- Converting a cron job's next-run timestamp into a human-readable date for a status page.
Common mistakes
- Mixing up seconds and milliseconds - passing a millisecond value to a system expecting seconds lands you in the year 55000+, and vice versa produces a date near 1970.
- Forgetting that a timestamp has no timezone of its own - always confirm whether you're reading the result in UTC or your local offset before comparing it to another value.
- Assuming timestamps account for leap seconds - Unix time does not, so it can drift by a second or two from true astronomical time over long periods.
Frequently asked questions
- What is a Unix timestamp?
- The number of seconds since 1970-01-01 00:00:00 UTC, also called the Unix epoch. Every instant in time maps to a single integer, which makes timestamps easy to store, sort, and compare across systems.
- Seconds or milliseconds?
- Unix timestamps are traditionally seconds (10 digits for current dates, e.g. 1735689600). JavaScript's Date.now() and Date.getTime() return milliseconds (13 digits, e.g. 1735689600000). If a value looks 1000x too large or too small, you likely have the unit wrong - this tool lets you pick which one you're working with.
- Why do I see different hours for UTC and local time?
- A Unix timestamp represents one fixed instant. UTC and local time are just different labels for that same instant, offset by your timezone (and possibly daylight saving time). The underlying timestamp never changes - only how it's displayed does.
- Can timestamps be negative?
- Yes. A negative Unix timestamp represents an instant before January 1, 1970. This is valid and many parsers handle it, but some older systems or 32-bit implementations may not, so treat pre-1970 dates as an edge case worth testing.
- What is the Year 2038 problem?
- Systems that store Unix time as a signed 32-bit integer will overflow at 2147483647 (2038-01-19 03:14:07 UTC). Modern 64-bit systems, including this converter, aren't affected, but it's worth knowing about if you're working with legacy code or embedded systems.