Epoch & Date Converter

About This Tool

The Unix epoch (also called Unix time or POSIX time) is a system for tracking time by counting the number of seconds that have elapsed since January 1, 1970 at 00:00:00 UTC (the Unix epoch). This tool converts Unix timestamps to human-readable dates and vice versa, supporting both seconds and milliseconds, multiple output formats (ISO 8601, RFC 2822, local date, UTC, relative time), and convenient presets for common timestamps like "now" or "start of today."

Unix timestamps are used extensively in programming because they provide a timezone-independent representation of time. Unlike date strings that vary by locale and timezone, a Unix timestamp represents the same instant everywhere on Earth. This makes them ideal for logging, database storage, API communication, and any system where consistent time representation matters. JavaScript uses milliseconds since the epoch (Date.now()), while most other systems and databases use seconds — a common source of confusion that this tool helps resolve.

Common Use Cases

• Debugging timestamp data from API responses and server access logs
• Converting database timestamps during development — databases often store timestamps in seconds
• Calculating time differences across timezones without manual offset math
• Generating timestamps for API requests that require Unix time format
• Understanding log file timestamps from systems that use epoch format
• Verifying expiration times in JWT tokens, SSL certificates, and cache headers

Pro Tips

• Unix epoch is in seconds by default — JavaScript uses milliseconds, so multiply seconds by 1000 (or divide milliseconds by 1000)
• Timestamps before 1970 appear as negative numbers (e.g., the Moon landing in 1969 is -14182900 seconds)
• The tool auto-detects whether your input is in seconds or milliseconds (timestamps over 10 digits are treated as milliseconds)
• Use the presets to quickly get common timestamps without manual calculation

Frequently Asked Questions

What is the Unix epoch?

The Unix epoch is January 1, 1970 at 00:00:00 UTC. Unix time is the number of seconds (or milliseconds) that have elapsed since that moment. It is the standard time representation used by most operating systems and programming languages.

What is the difference between seconds and milliseconds?

Unix time is defined in seconds. However, JavaScript's Date.now() returns milliseconds, which is 1000 times larger. A timestamp of 1716768000 seconds equals 1716768000000 milliseconds. This tool auto-detects which one you have entered.

Will Unix timestamps overflow?

The Year 2038 problem is the largest risk — when 32-bit signed Unix timestamps overflow. On January 19, 2038 at 03:14:07 UTC, the maximum 32-bit value is reached. Most modern systems use 64-bit time, which will not overflow for billions of years.

Why is my timestamp showing the wrong date?

The most common issue is mixing up seconds and milliseconds. If your timestamp appears to be in the year 50,000+, you probably entered seconds but the tool is reading them as milliseconds, or vice versa. The tool auto-detects, but you can verify by checking the detected unit.

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