About this Unix Timestamp
Computers count time differently than humans. Instead of years, months, and days, Unix systems track a single integer: the number of seconds that have elapsed since midnight on January 1, 1970 (UTC). This is called the 'Unix Epoch'. This tool converts that raw number into a readable date and vice-versa.
Who this calculator is for
- Developers, analysts, and technical users converting between Unix time and human-readable dates.
- Anyone debugging API payloads, logs, exports, or database fields that store epoch values.
- Users who need a quick browser-based conversion without opening a terminal or writing code.
When to use it
- Decode a Unix timestamp from logs, APIs, or databases into readable local and UTC dates.
- Convert a known date and time into epoch seconds for testing, scripting, or integrations.
- Cross-check UTC-based values before moving on to timezone or date-difference calculations.
How to use this calculator
- Select Date -> Timestamp to convert a readable date into a Unix integer.
- Select Timestamp -> Date to decode a Unix integer into a readable string.
- Enter the value and see the result instantly.
Key assumptions
- Standard Unix timestamps are treated as seconds since January 1, 1970 00:00:00 UTC.
- Date input uses the browser's local timezone before conversion to the UTC-based epoch value.
- This tool expects 10-digit second timestamps rather than 13-digit millisecond values unless you convert them first.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
How this calculator works
The Unix Timestamp is a simple count of seconds.
* To Timestamp: Calculate the difference in milliseconds between the input date and Jan 1, 1970 00:00:00 UTC, then divide by 1000.
* To Date: Multiply the timestamp by 1000 to get milliseconds, then create a new Date object.
Inputs explained
Mode
Choose the direction of conversion.
Date/Time
The human-readable local time you want to convert.
Timestamp
The integer representing seconds since the Epoch.
Understanding your results
The Timestamp is a 10-digit number (currently). The Date result shows both local time and UTC (Coordinated Universal Time) for reference.
Example scenarios
The Epoch
Date: 1970-01-01 00:00:00 UTC. Timestamp: 0.
Billions
Timestamp: 1,600,000,000. Date: Sept 13, 2020.
Key Features
- Bidirectional conversion
- Local & UTC display
- Live calculation
Tips & Best Practices
- JavaScript uses milliseconds internally (13 digits), while standard Unix timestamps are seconds (10 digits).
- Negative timestamps represent dates before 1970.
Glossary of Terms
- Epoch
- The starting point for Unix time: January 1, 1970, at 00:00:00 UTC.
- UTC
- Coordinated Universal Time. The primary time standard by which the world regulates clocks.
- Y2038
- The 'Year 2038 problem' is when 32-bit signed integers will overflow the max timestamp value on Jan 19, 2038.