Unix Timestamp Converter — Date ↔ Epoch
Convert between Unix timestamps and human-readable dates. Supports seconds and milliseconds. Essential for developers and APIs.
Why This Technology Metric Matters
Why: Unix timestamps are universal for storing dates in databases and APIs. Converting correctly avoids bugs.
How: Timestamp is parsed; 10 digits = seconds, 13 = ms. Date uses getTime() for ms output.
- ●10 digits = seconds; 13 = milliseconds
- ●JavaScript uses milliseconds
- ●Year 2038 problem for 32-bit
Sample Scenarios — Click to Load
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Conversion Steps
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⚠️For educational and informational purposes only. Verify with a qualified professional.
🔧 Tech Milestones
Unix Epoch: Jan 1, 1970 00:00:00 UTC
— Unix
1B seconds = Sep 9, 2001
— Wikipedia
Year 2038: 32-bit signed overflow
— IEEE
Unix timestamp counts seconds (or milliseconds) since Jan 1, 1970 00:00:00 UTC. 10 digits = seconds; 13 = milliseconds. JavaScript Date uses ms; many APIs use seconds. All conversions use UTC.
Key Takeaways
- • Unix timestamp is seconds since Jan 1, 1970 00:00:00 UTC
- • 10 digits = seconds; 13 digits = milliseconds
- • JavaScript Date uses milliseconds; multiply/divide by 1000 as needed
- • Year 2038 problem: 32-bit signed max at 2,147,483,647
Frequently Asked Questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds (or milliseconds) since January 1, 1970 00:00:00 UTC (the Unix epoch). It is a universal way to store dates in databases and APIs.
What is the difference between seconds and milliseconds?
10-digit timestamps are seconds; 13-digit are milliseconds. JavaScript Date uses milliseconds; many APIs use seconds. Multiply or divide by 1000 to convert.
What is the Year 2038 problem?
32-bit signed integers max out at 2,147,483,647 seconds, which falls on January 19, 2038. Systems using 32-bit time will overflow. Use 64-bit or unsigned for dates beyond 2038.
Why use UTC?
Unix timestamps are always in UTC (Coordinated Universal Time). This avoids timezone confusion when storing or transmitting dates across systems.
How do I convert a date to timestamp?
Enter a date string (e.g., 2025-02-16 or ISO format) and switch to "Date to Timestamp" mode. The calculator outputs both seconds and milliseconds.
What format does the output use?
Timestamp-to-date outputs ISO 8601 format (e.g., 2025-02-16T00:00:00.000Z). Date-to-timestamp outputs Unix seconds and milliseconds.
⚠️ Disclaimer: Conversions use UTC. Local time varies by timezone. Not responsible for timezone-related bugs.