Date Time Converter

Free online tool. All processing is client-side. No signup needed.

How to Use the Date Time Converter

1. Enter your input values above
2. Results update automatically
3. Copy or download the output

What is a Date Time Converter?

A Date Time Converter transforms dates and times between formats, time zones, and representations — Unix timestamps, ISO 8601, RFC 2822, relative time ('2 hours ago'), and formatted dates in any locale. Every developer working with APIs, databases, and logs encounters multiple date formats daily: Python uses one format, JavaScript another, MySQL a third, and humans prefer a fourth. This tool is the universal translator for dates and times: paste any date/time representation and see it in all other relevant formats instantly.

How Does It Work?

Enter a date/time in any recognized format, or enter a Unix timestamp (seconds or milliseconds since 1970-01-01). The converter parses it and displays: (1) ISO 8601 (2026-06-09T15:30:00Z), (2) RFC 2822 (Mon, 09 Jun 2026 15:30:00 +0000), (3) Unix timestamp (seconds and milliseconds), (4) relative time (5 minutes ago, in 3 days), (5) formatted output in your chosen locale and format string, (6) day of week, week number, quarter. All time zone conversions happen simultaneously: UTC, your local time, and any other zone you select.

Formula

Unix Timestamp: seconds (or milliseconds) since 1970-01-01T00:00:00Z\n\nISO 8601: YYYY-MM-DDTHH:mm:ss.sssZ\nRFC 2822: Day, DD Mon YYYY HH:mm:ss ±ZZZZ\n\nDate Format Tokens:\n• YYYY = 4-digit year | YY = 2-digit year\n• MM = month (01-12) | MMM = Jan | MMMM = January\n• DD = day (01-31) | Do = 1st, 2nd, 3rd\n• HH = hour (00-23) | hh = hour (01-12)\n• mm = minute | ss = second | sss = millisecond\n• A = AM/PM | Z = timezone offset\n\nRelative Time:\n• < 60s: 'just now'\n• < 1hr: 'X minutes ago/in X minutes'\n• < 24hr: 'X hours ago/in X hours'\n• < 30d: 'X days ago/in X days'\n• > 30d: 'on [date]'

Who Uses This Tool?

• Developers converting between Unix timestamps and human-readable dates
• API consumers parsing ISO 8601 dates from JSON responses
• System administrators reading timestamped log entries
• International teams converting meeting times across time zones
• Anyone seeing a Unix timestamp and wondering what date/time it represents

Pro Tips

• Unix timestamps can be seconds OR milliseconds — if the number is 10 digits, it's seconds; if 13 digits, it's milliseconds. Our converter auto-detects
• ISO 8601 is the international standard for date exchange. Always use it in APIs and databases: YYYY-MM-DDTHH:mm:ssZ. It's unambiguous across all cultures
• When displaying dates to users, use their local timezone and locale-appropriate formatting. 06/09/2026 means June 9 in the US but September 6 in the UK
• The year 2038 problem: 32-bit Unix timestamps overflow on 2038-01-19. Modern systems use 64-bit timestamps which are safe for 292 billion years

Frequently Asked Questions about Date Time Converter

What's the difference between UTC and GMT?

UTC (Coordinated Universal Time) is the modern time standard, based on atomic clocks with occasional leap seconds. GMT (Greenwich Mean Time) is the older solar-time-based standard. For most practical purposes, they're equivalent, but UTC is the correct technical term.

Why do I see timestamps in seconds and milliseconds?

Unix/Linux systems traditionally use seconds. JavaScript uses milliseconds (Date.now()). Many APIs use milliseconds for higher precision. Check the magnitude: 10 digits ≈ seconds, 13 digits ≈ milliseconds.

Free online Date Time Converter — no signup, 100% client-side processing. All data stays in your browser.