Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates. Bidirectional, real-time.
?Tips
- 10-digit numbers are treated as seconds, 13-digit numbers as milliseconds (auto-detected).
- Use the date picker for quick conversions without typing ISO strings.
- The "Relative" field shows human-readable time differences (e.g., "3 hours ago").
- All results include both UTC and your local timezone for comparison.
- Press Cmd+Enter to convert the current input.
Understanding Unix Timestamps
A Unix timestamp counts seconds since January 1, 1970 00:00:00 UTC (the Unix Epoch). This single integer encodes a precise moment independent of time zones, DST, or calendar systems, making it the standard for machine-to-machine time communication.
Timestamps simplify date math: differences become subtraction, duration additions become addition, and comparisons become numeric. Databases, APIs, log files, and auth tokens all use Unix timestamps for their unambiguity and compactness.
Timestamps can be seconds (10 digits for current dates) or milliseconds (13 digits). JavaScript Date.now() returns milliseconds; most server languages use seconds. Our converter auto-detects the format by checking if the value exceeds one trillion.
The Year 2038 Problem affects 32-bit signed integer timestamps, which max out at 2,147,483,647 (January 19, 2038). Modern systems use 64-bit timestamps, extending the range to approximately 292 billion years.
ISO 8601 (2024-03-15T10:30:00Z) is the human-readable standard for date strings. While readable, it requires parsing for computations, which is why Unix timestamps remain preferred for programmatic use.