Unix Timestamp Converter Online
Convert Unix epoch timestamps to UTC, ISO 8601, and local time — or convert any date back to a Unix timestamp. Supports seconds and milliseconds. No signup, runs entirely in your browser.
How the Unix Timestamp Converter Works
- 1Choose a direction: convert a timestamp to a readable date, or a date/time to a timestamp.
- 2Select precision: seconds (10-digit timestamps) or milliseconds (13-digit timestamps from JavaScript's Date.now()).
- 3Enter your timestamp or pick a date. Click Use Now to instantly load the current time.
- 4Click Convert — the result shows UTC, ISO 8601, your local time, and a relative label (e.g. "3 days ago").
Why Unix Timestamps Are Used in Software
Unix timestamps are timezone-agnostic integers — the same number represents the same moment everywhere on Earth. This makes them ideal for storing time in databases, comparing two events across timezones, and passing time values between systems. Converting to a human-readable format only happens at display time, using the viewer's local timezone.
Common Timestamp Reference Points
Unix Epoch
Timestamp 0 = January 1, 1970, 00:00:00 UTC. All Unix timestamps count seconds from this reference point.
JavaScript Date.now()
Returns milliseconds — a 13-digit number. Divide by 1000 to get the standard seconds-precision Unix timestamp.
Year 2038 Problem
32-bit signed integers overflow at timestamp 2147483647 (Jan 19, 2038). 64-bit systems handle dates well beyond the year 292 billion.
Database Storage
PostgreSQL uses TIMESTAMPTZ (stores UTC internally). MySQL uses DATETIME or TIMESTAMP. Use UTC for all storage and convert to local time at display.
Negative Timestamps
Timestamps before 1970 are negative integers. January 1, 1960 = −315619200. Most systems handle these correctly.
ISO 8601 vs Unix
ISO 8601 (2024-01-15T14:30:00Z) is human-readable and sortable as a string. Unix timestamps are more compact and faster to compare numerically.
Frequently Asked Questions
What is a Unix timestamp?
A Unix timestamp (also called epoch time) is the number of seconds elapsed since January 1, 1970 at 00:00:00 UTC — a point in time called the Unix epoch. It provides a simple, timezone-independent way to represent any moment in time as a single integer. As of 2026, the current Unix timestamp is approximately 1,747,000,000.
What is the difference between seconds and milliseconds timestamps?
Most Unix timestamps are in seconds (a 10-digit number like 1700000000). JavaScript's Date.now() returns milliseconds (a 13-digit number like 1700000000000). Databases, server logs, and most POSIX APIs use seconds. JavaScript, Java, and .NET typically use milliseconds. If your number is 13 digits, switch the precision toggle to milliseconds before converting.
What timezone does this tool use?
The tool shows results in three formats simultaneously: UTC (always consistent), ISO 8601 (UTC with Z suffix), and your local timezone as detected by your browser. When converting a date to a timestamp, the date picker uses your local time — so 2024-01-15T14:00 means 2pm in your local timezone.
What is the Unix timestamp for a specific date?
Switch the tool to "Human → Timestamp" mode, pick your date and time, and click Convert. Common reference points: 2000-01-01 00:00:00 UTC = 946684800; 2024-01-01 00:00:00 UTC = 1704067200; 2030-01-01 00:00:00 UTC = 1893456000.
What is the Year 2038 problem?
32-bit systems store Unix timestamps as a signed 32-bit integer, which overflows on January 19, 2038 at 03:14:07 UTC (timestamp 2147483647 + 1 = −2147483648). Modern 64-bit systems are not affected. Most server software and databases switched to 64-bit timestamps before 2010. If you are working with embedded systems or legacy code that stores time as a 32-bit integer, the 2038 problem is still relevant.
Is my data private? Are the timestamps sent to a server?
No. All conversion runs in your browser using JavaScript. No timestamp, date, or result is transmitted to any server. The live current-timestamp counter also runs locally — it simply reads Date.now() in your browser every second.
What is ISO 8601 format?
ISO 8601 is an international standard for representing dates and times. A timestamp in ISO 8601 format looks like 2024-01-15T14:30:00.000Z, where the T separates the date and time and Z indicates UTC. This format is unambiguous, sortable lexicographically, and supported by all modern programming languages.