Date and Time Format Converter
Description
Transform dates and timestamps between various formats, including Unix timestamps, ISO strings, and custom patterns. Ideal for debugging and API integrations.
About Date and Time Format Converter
Dates rarely arrive in the format you need. This converter translates a single moment between Unix timestamps (in seconds or milliseconds), ISO 8601 strings, and human-readable formats so you can read logs, debug APIs, and reconcile timezone differences at a glance. Everything is computed entirely in your browser, so no dates or timestamps ever leave your device.
How to use
- Paste or type a value into the input, such as a Unix timestamp or an ISO 8601 date string.
- Pick the format your input is in.
- Choose the target format and, where relevant, the timezone (UTC or your local zone).
- Read the converted result and copy it for use in your code, tests, or API requests.
Examples
| Example | Input | Output |
|---|---|---|
| Unix epoch to ISO 8601 | 0 | 1970-01-01T00:00:00.000Z |
Frequently asked questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds elapsed since the Unix epoch, which is 1970-01-01T00:00:00Z (midnight UTC on January 1, 1970). Many systems also use milliseconds, which is 1000 times larger for the same instant.
What is the difference between seconds and milliseconds?
Unix timestamps in seconds are typically 10 digits for current dates, while millisecond timestamps are 13 digits. JavaScript's Date.now() returns milliseconds, whereas many backend languages use seconds, so check the magnitude before converting.
How are timezones handled?
Unix timestamps and ISO 8601 strings ending in Z are absolute and tied to UTC. When you display a date in a human-readable local format, the converter applies an offset, so the same instant can show different clock times in different timezones.
Is my data sent to a server?
No. All parsing and conversion happen locally in your browser using built-in date functions, so the dates and timestamps you enter are never uploaded anywhere.