Unix Timestamp Converter
Convert a Unix epoch timestamp into a readable date — and convert a calendar date back into a timestamp. This free online developer calculator runs entirely in your browser — no signup, no data sent anywhere.
Inputs
Results
How It Works (Formula & Method)
To convert a timestamp, the seconds value is multiplied by 1000 (JavaScript dates use milliseconds) and formatted as a UTC string and an ISO 8601 string. To convert a date, the entered string is parsed into a date object and the millisecond value is divided by 1000 to produce the epoch seconds.
Worked Example
Below is a worked example using the calculator's default values. The same numbers are pre-filled in the form above so you can press Calculate and see the result without typing anything.
Inputs used:
- Unix Timestamp (seconds): 1735689600
- Date String (YYYY-MM-DD HH:MM:SS): 2026-01-01 00:00:00
With these inputs, the calculator computes the metrics shown in the Results panel. Change any value and press Calculate again to see how the result responds — the live widget and the chart both update instantly.
About the Unix Timestamp Converter
A Unix timestamp is the number of seconds elapsed since midnight UTC on 1 January 1970 — the "epoch." It is the standard way computers store time because it is a single integer with no time zone ambiguity. Databases, log files, and APIs use it constantly, but it is not human-readable. This tool converts in both directions.
Tips & Considerations
- Most systems store timestamps in seconds; JavaScript and some APIs use milliseconds. Watch for a 1000× difference.
- The 32-bit signed timestamp overflows on 19 January 2038 — the "Year 2038 problem." Modern systems use 64-bit timestamps.
- Timestamps are always UTC. Apply a time-zone offset only when displaying to a user.
Frequently Asked Questions
What is the Unix epoch?
The epoch is the reference moment from which Unix time is counted: 00:00:00 UTC on 1 January 1970. A timestamp is the count of seconds since then.
Why use timestamps instead of date strings?
A timestamp is a single integer with no formatting or time-zone ambiguity, making it trivial to store, compare, sort, and do arithmetic on.
What is the Year 2038 problem?
Systems that store the timestamp as a signed 32-bit integer can only count to 03:14:07 UTC on 19 January 2038. After that the value overflows. The fix is to use a 64-bit integer.
What does the Unix Timestamp Converter compute?
The Unix Timestamp Converter takes 2 input values and returns 2 results. Convert a Unix epoch timestamp to a human-readable date, and convert a date back to a timestamp.