How to use Unix Timestamp Converter
The Unix Timestamp Converter translates between Unix timestamps (seconds or milliseconds since 1970-01-01T00:00:00Z) and human-readable date-time strings in any timezone. Unix time is the universal currency of time in computing — used in database records, HTTP headers, JWT claims, log files and cryptographic certificates — making a reliable converter an everyday tool for developers and system administrators.
- To convert a Unix timestamp to a date, enter the numeric value in the "Timestamp" field and select seconds or milliseconds.
- Select your target timezone from the dropdown (or use UTC for a canonical result).
- The corresponding ISO 8601 date, local date string and day-of-week are displayed instantly.
- To convert a date to a Unix timestamp, switch to the "Date → Timestamp" tab.
- Enter the year, month, day, hour, minute and second, choose the timezone, and click Convert.
- Copy the numeric timestamp for use in API calls, database queries or configuration files.
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Unix time and the epoch
Unix time counts the number of non-leap seconds elapsed since the Unix epoch: midnight UTC on 1 January 1970. It ignores leap seconds, making it monotonic and easy to compute differences between timestamps with simple subtraction. A 32-bit signed Unix timestamp overflows on 19 January 2038 at 03:14:07 UTC — the Year 2038 Problem (Y2K38). Modern systems use 64-bit integers that will not overflow for approximately 292 billion years.
Milliseconds, microseconds and ISO 8601
JavaScript's Date.now() and many REST APIs return timestamps in milliseconds (ms) rather than seconds, so the value is 1,000 times larger. Some high-precision systems (databases, tracing tools) use microseconds or nanoseconds. ISO 8601 (e.g., 2024-06-15T14:30:00Z) is the standardised human-readable representation and is unambiguous across locales — always prefer it over locale-specific formats in API responses and log files. The trailing Z denotes UTC; offsets are expressed as ±HH:MM.
| Unit | Digits (approx.) | Example value | Common source |
|---|---|---|---|
| Seconds | 10 | 1718457600 | Unix stat, JWT exp/iat, HTTP headers |
| Milliseconds | 13 | 1718457600000 | JavaScript Date.now(), REST APIs |
| Microseconds | 16 | 1718457600000000 | PostgreSQL, Python time.time_ns() |
| Nanoseconds | 19 | 1718457600000000000 | Go time.Now().UnixNano(), Linux clock_gettime |
Worked examples
Unix seconds to date
Inputs: 1735689600 (seconds)
Result: Wed, 1 Jan 2025 00:00:00 UTC
Milliseconds timestamp
Inputs: 1735689600000 (13 digits)
Result: same instant — divide by 1000 for seconds
Date to timestamp
Inputs: 2025-01-01T00:00:00Z
Result: 1735689600
Notable Unix timestamps reference
| Date (UTC) | Unix seconds |
|---|---|
| 1970-01-01 00:00:00 | 0 (the epoch) |
| 2001-09-09 01:46:40 | 1000000000 |
| 2009-02-13 23:31:30 | 1234567890 |
| 2025-01-01 00:00:00 | 1735689600 |
| 2038-01-19 03:14:07 | 2147483647 (signed 32-bit max) |
Glossary
- Unix epoch
- The reference point of Unix time: midnight UTC on 1 January 1970.
- UTC
- Coordinated Universal Time — the primary time standard by which the world regulates clocks.
- ISO 8601
- An international standard for representing dates and times as strings, e.g. 2024-06-15T14:30:00Z.
- Y2K38
- The Year 2038 Problem — 32-bit Unix timestamps overflow on 19 January 2038.
- Leap second
- An occasional one-second adjustment to UTC; Unix time ignores leap seconds and treats each day as exactly 86,400 seconds.
Related reading
Frequently Asked Questions
Why use Unix Timestamp Converter?
- Convert Unix timestamps to human-readable ISO 8601 dates in any timezone
- Convert a date and time back to a precise Unix timestamp for API calls or JWT claims
- Handle both second-precision and millisecond-precision timestamps from different systems
- Show the day-of-week alongside the converted date for quick calendar sanity checks
Common use cases
- Decode a JWT exp claim value to check the actual token expiry date and time
- Convert a database UNIX_TIMESTAMP() value to a readable date for a bug report
- Compute the Unix timestamp for a scheduled event in a specific timezone
- Debug a caching header by converting a Last-Modified epoch value to a readable date
- Verify that a UTC server log timestamp matches the expected local time for an incident
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