🛠️ Time Playground

Interactive tools to explore the dark corners of time handling. Test DST transitions, parse timestamps, and discover why your cron job failed at 2:30 AM.

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DST Simulator

Pick a city and scrub through spring-forward/fall-back windows. Watch "nonexistent" and "ambiguous" times appear.

Interactive • Real DST data • Visual timeline

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Epoch Converter

Unix timestamp to human-readable and vice versa. Handle seconds vs milliseconds confusion.

Unix time • Milliseconds • Y2K38 awareness

🔬

Format Lab

Paste any timestamp and see how different parsers interpret it. RFC 3339 vs ISO 8601 vs locale madness.

Multi-format • Parser comparison • Edge cases

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Timezone Converter

Safe timezone conversions with code examples. Learn the difference between naive and aware datetimes.

Code examples • Best practices • Multiple languages

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Week Number Explorer

ISO week vs calendar week calculator. Discover why December 30th can belong to next year.

ISO 8601 • Calendar systems • Year boundaries

💡 Quick Tips

Always store UTC

Convert to local time only for display

Use timezone-aware libraries

Luxon, date-fns-tz, or Python's zoneinfo

Test DST transitions

Spring forward and fall back edge cases

Never trust local time

It can be ambiguous or nonexistent

Avoid naive datetimes

Always include timezone information

Don't schedule at 2:30 AM

This time doesn't exist during spring forward