Date & Time
Unix Timestamp Converter
Convert Unix timestamps to dates and back.
What is this tool?
APIs, logs, and databases often store time as a Unix timestamp, a bare number like 1700000000 that means nothing at a glance. This converter shows the exact moment it represents in UTC, in your local timezone, and in ISO 8601, and turns dates back into epoch seconds and milliseconds.
Unix time counts seconds (or milliseconds) since 1970-01-01T00:00:00Z. APIs often mix seconds and milliseconds — ToolForge helps you tell them apart.
Auto-detection treats absolute values below 1e12 as seconds and larger values as milliseconds.
How to use the Timestamp Converter
- Paste a Unix timestamp (seconds or milliseconds) or a date string.
- Choose the unit if auto-detection is wrong.
- Read ISO, UTC, and local representations, plus both second and millisecond epochs.
Examples
Seconds to ISO
1700000000
2023-11-14T22:13:20.000Z
Frequently asked questions
Why is my date off by a few hours?
Local time depends on your timezone. Compare the UTC and local fields to confirm.
How can I tell seconds from milliseconds?
Present-day timestamps have 10 digits in seconds and 13 digits in milliseconds. The converter detects the unit automatically, and you can override it.
What is the Year 2038 problem?
Systems that store Unix time as a signed 32-bit integer overflow on January 19, 2038. JavaScript uses 64-bit numbers, so this converter handles dates far beyond that.
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