Timestamp Converter

About Timestamp Converter

A Unix timestamp (also called Epoch time or POSIX time) is the number of seconds that have elapsed since January 1, 1970 00:00:00 UTC — a point in time known as the Unix epoch. Many programming languages, databases, APIs, and logging systems store dates as timestamps because they are timezone-independent and easy to compare arithmetically.

This tool converts timestamps to human-readable date/time strings showing both your local timezone and UTC, and converts dates back to timestamps. It supports both seconds (10-digit) and milliseconds (13-digit) formats, which is important since JavaScript and many modern APIs use milliseconds while traditional Unix systems use seconds.

How to Use Timestamp Converter

1. Timestamp to Date: Enter a numeric timestamp (e.g., 1700000000), check "Milliseconds" if it is in milliseconds, and see the converted date in both local and UTC time.
2. Date to Timestamp: Select a date and time using the datetime picker (in your local timezone) and view the corresponding Unix timestamp.
3. Click Use current time to fill both fields with the current moment.
4. Use Copy timestamp to copy the numeric value to your clipboard.

Key Features

• Bidirectional conversion — Timestamp to date and date to timestamp
• Seconds & milliseconds — Supports both 10-digit (seconds) and 13-digit (milliseconds) formats
• Dual timezone display — Shows results in both local time and UTC
• Current time shortcut — One click to capture the current moment
• Client-side processing — No server communication; your data stays private

When to Use This Tool

• Decoding timestamps from API responses, log files, or database records
• Generating a specific timestamp for testing, queries, or configuration
• Checking what date and time a given timestamp represents in your timezone
• Converting between seconds and milliseconds timestamp formats
• Verifying token expiration times (e.g., JWT exp claims)

Technical Details

Timestamps are always based on UTC. The "Date & time (local)" input uses your browser's timezone, determined by the Intl API. Values with 13 digits (e.g., 1700000000000) are typically in milliseconds; 10-digit values are in seconds. The tool uses JavaScript's Date object for conversions, which supports dates from approximately 271,821 BCE to 275,760 CE. For more date calculations, try Days Between Dates or Age Calculator.

Conclusion

Timestamp Converter is an indispensable tool for developers and system administrators who work with Unix timestamps daily. With bidirectional conversion, seconds/milliseconds support, and dual timezone display, it makes decoding and generating timestamps effortless — all within your browser. For timezone comparisons, try the Timezone Converter.