DataToolsLab

Date & Time Tools

Free, privacy-first date and time utilities built on the browser's native Date and Intl APIs. Convert Unix timestamps, calculate date differences and business days, decode cron expressions, and more — all locally in your browser.

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About Date & Time Tools

Working with dates and times is one of the most common — and most error-prone — developer tasks. Our Date & Time tools handle conversions, calculations, and timezone math entirely in your browser using the native Intl/Date APIs, so your data never leaves your device.

Frequently asked questions

What is a Unix timestamp and how does it work?

A Unix timestamp is the number of seconds (or milliseconds) that have elapsed since January 1, 1970 00:00:00 UTC. Our converter translates between these numbers and human-readable dates in any timezone.

Why do timezone conversions sometimes seem off by an hour?

Usually it's daylight saving time: the offset for a timezone changes across the year. Converting with a fixed offset instead of the timezone's rules (as Intl.DateTimeFormat does) produces wrong results around DST transitions.

Do these tools upload my dates?

No. Every Date & Time tool runs entirely in your browser using the native Date and Intl APIs. Nothing is sent to a server.

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