Timestamp Converter Online - Free Unix Epoch Tool

Convert Unix timestamps to dates and vice versa. Fast, secure, and completely free. All processing happens in your browser — no data is sent to any server.

What is a Timestamp Converter?

A Timestamp Converter translates between Unix time — the number of seconds (or milliseconds) elapsed since January 1, 1970 UTC — and human-readable calendar dates, in either direction. Unix timestamps are how most systems store and pass dates internally because they're a single unambiguous number with no timezone attached, but that same property makes them unreadable at a glance: 1735689600 means nothing to a person until it's converted to 'January 1, 2025 00:00:00 UTC'.

How to Use Timestamp Converter

1. Paste a Unix timestamp (seconds or milliseconds) to convert it to a readable date, or enter a date to get its timestamp
2. Select the target timezone for the readable date display
3. Toggle between seconds and milliseconds if you're unsure which unit your source data uses
4. Copy either the timestamp or the formatted date, depending on which direction you need
5. Use 'Now' to instantly get the current timestamp for testing

Key Features

• Bidirectional conversion: timestamp to date and date to timestamp
• Supports both seconds and millisecond-based timestamps
• Converts to any timezone, not just UTC or your local timezone
• Instant 'current timestamp' lookup
• Handles the full valid range of Unix time, including dates before 1970 (negative timestamps)

Why Use Timestamp Converter?

Reading a raw timestamp value out of a database row, an API response, or a log line tells you nothing until it's converted, and doing that mental math (accounting for seconds vs. milliseconds, and which timezone applies) is genuinely error-prone by hand. Converting instantly is the fastest way to confirm whether a stored expiration timestamp is actually in the past, whether a log entry's timing lines up with a reported incident, or whether an API is sending seconds when your code expects milliseconds (a classic off-by-1000 bug).

Common Use Cases

• Checking whether a stored expiration or scheduled timestamp has actually passed
• Converting a log timestamp to local time while investigating an incident
• Debugging a seconds-vs-milliseconds mismatch between two systems
• Verifying an API response's timestamp field against the expected format
• Generating a specific timestamp value for a test fixture

Frequently Asked Questions

Why is my timestamp 13 digits long instead of 10?

10-digit timestamps are in seconds; 13-digit timestamps are in milliseconds. JavaScript's Date.now() returns milliseconds, while many backend languages and Unix tools default to seconds — mixing them up is one of the most common timestamp bugs.

Can Unix timestamps represent dates before 1970?

Yes, using negative numbers — a timestamp of -86400 represents December 31, 1969, exactly one day before the epoch. Most systems handle negative timestamps correctly, though some edge-case libraries don't.

Does a Unix timestamp include timezone information?

No — a Unix timestamp is always an absolute point in time relative to UTC; the timezone is applied only when converting it into a human-readable date, which is why the same timestamp displays differently depending on the timezone you select.

What's the maximum date a 32-bit Unix timestamp can represent?

A signed 32-bit timestamp overflows on January 19, 2038 (the 'Year 2038 problem') — modern systems using 64-bit timestamps don't have this limitation, but legacy 32-bit systems can still be affected.

Is 'now' generated from my computer's clock or a server?

It's read directly from your browser's local system clock, so if your device's clock is set incorrectly, the displayed 'current timestamp' will reflect that.

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