Free Online Timestamp Converter
Convert a Unix timestamp (seconds or milliseconds) to a readable date and time, or convert any date back to a Unix timestamp. Hit "Use Current Time" to see the live epoch value.
What is a Unix Timestamp?
A Unix timestamp (also called Unix time, POSIX time, or Epoch time) is the number of seconds elapsed since 00:00:00 UTC on 1 January 1970 — the Unix epoch. It is an integer that increases by 1 every second, making it trivial to calculate durations and sort events chronologically regardless of time zone.
Many programming languages and databases store timestamps as integers. JavaScript uses milliseconds (multiply seconds by 1 000), while most Unix tools, databases like PostgreSQL, and API responses use seconds. This converter handles both — if your number is larger than 10¹⁰, it is treated as milliseconds.
Output Formats
ISO 8601
The international standard: 2024-01-15T14:30:00.000Z. Always UTC, machine-readable, sortable as a string. The recommended format for APIs and logs.
UTC
Human-readable UTC string: Mon, 15 Jan 2024 14:30:00 GMT. The format used by HTTP headers (Date, Last-Modified).
Local Time
The date and time in your browser's local time zone, formatted according to your system locale. Useful for quickly checking what a timestamp means in your own time zone.
Common Use Cases
- Log file analysis: Convert raw epoch timestamps in server logs to readable dates to identify when an event occurred.
- API debugging: Inspect
created_at/expires_atfields returned by REST or GraphQL APIs. - Database timestamps: Translate Unix integers stored in a database column to human-readable dates for reporting.
- Scheduling & cron: Convert a target date and time to an epoch value for use in scheduled task configurations.
Frequently Asked Questions
This converter detects it automatically: if the number is larger than 10¹⁰ (10 billion), it's treated as milliseconds; otherwise it's treated as seconds. As a rule of thumb, a 10-digit number is seconds and a 13-digit number is milliseconds for current dates.
Unix timestamps themselves have no time zone — they're a count of seconds since a fixed UTC moment. This tool shows the result in UTC and in your browser's local time zone side by side, so you can read whichever one you need.
Yes, Unix timestamps can be negative to represent dates before the epoch (1 January 1970 UTC) — the converter handles negative values correctly in both directions.
It comes down to language convention: Unix tools, most databases (like PostgreSQL), and many REST APIs use seconds, while JavaScript's Date object and many web APIs use milliseconds for finer precision. Always check the specific API's documentation if you're unsure.
It's completely free with no limits, and nothing is sent anywhere — conversion happens entirely in your browser using JavaScript.