Timestamp Converter
Time & Date · Free Online Tool
Convert Unix timestamps to dates and back.
This tool runs interactively in your browser. Please visit ez4code.com/tools/timestamp-converter to use it.
How to Use Timestamp Converter
- 1Enter the time, date, or value you want to convert.
- 2Select the target format or timezone.
- 3The tool calculates the result instantly.
- 4Copy the converted value for your use.
Features
- ✓100% free — no signup, no subscription, no ads
- ✓Runs entirely in your browser — data never leaves your device
- ✓Fast and lightweight — instant results
- ✓Cross-platform — works on desktop, tablet, and mobile
What is Timestamp Converter?
A Unix timestamp is the number of seconds (or milliseconds) elapsed since the Unix epoch: 1970-01-01 00:00:00 UTC, excluding leap seconds. Defined by POSIX.1, it is the standard time representation in Unix systems, databases, and APIs. Timestamps are timezone-independent (always UTC).
How does Timestamp Converter work?
The converter parses timestamps (seconds or milliseconds) and creates a JavaScript Date object. The Date is displayed in UTC and the user's local timezone. Reverse conversion takes a date string, parses it, and computes (date.getTime() - epoch) / 1000.
Common Use Cases
- ✓API parameters — pass time as integer to avoid timezone ambiguity
- ✓Database storage — store timestamps for consistent ordering
- ✓Cache expiry — compute TTL in seconds
- ✓Log analysis — correlate events across timezones
Unix Timestamp vs ISO 8601
Timestamps are compact integers, ideal for storage and computation. ISO 8601 strings (e.g., 2024-01-15T10:30:00Z) are human-readable and self-describing (includes timezone). Use timestamps for internal storage and computation; use ISO 8601 for API responses and human display. Most databases support both.
Security & Privacy
This tool runs entirely in your browser. Timestamps themselves have no security concerns, but be aware of the Y2038 problem: 32-bit signed integer timestamps overflow on 2038-01-19 03:14:07 UTC. Use 64-bit integers (bigint) for future-proofing.
Technical Details
Epoch: 1970-01-01 00:00:00 UTC (POSIX.1). Seconds: 10-digit (until 2286). Milliseconds: 13-digit (JavaScript Date.getTime()). Y2038 limit: 2147483647 (2^31-1) on 32-bit systems. Leap seconds: NOT counted in Unix time. JavaScript Date range: ±8,640,000,000,000,000 ms (±275,760 years). ISO 8601 format: YYYY-MM-DDTHH:mm:ss.sssZ.
Frequently Asked Questions
What is the Y2038 problem?
32-bit signed Unix timestamps overflow on 2038-01-19 03:14:07 UTC. Systems using 32-bit time_t will break. Most 64-bit systems are unaffected. Use 64-bit integers to be safe.
Does Unix time include leap seconds?
No. POSIX.1 defines Unix time without leap seconds. Each day is exactly 86400 seconds. Leap seconds are handled by smear or repeated seconds at the application level.
Seconds or milliseconds?
Unix systems traditionally use seconds. JavaScript, Java, and most web APIs use milliseconds. 13-digit = milliseconds; 10-digit = seconds. Always check your API documentation.
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