What is a Unix Timestamp and Why Convert It?

A Unix timestamp (also called POSIX time or Epoch time) is the number of seconds that have elapsed since January 1, 1970 at 00:00:00 UTC (Coordinated Universal Time). This date is called the Unix Epoch. Timestamps are widely used in computing because they're simple, timezone-agnostic, and easy to compare. Instead of storing "March 15, 2024 at 2:30 PM EST", you store "1710516600" — a single integer that represents the exact moment worldwide.

Where Are Timestamps Used?

Databases: MySQL, PostgreSQL, and MongoDB store timestamps for created_at and updated_at fields. APIs: REST and GraphQL APIs return timestamps in JSON responses. Log Files: Server logs, application logs, and error tracking use timestamps. File Systems: File creation, modification, and access times. JWT Tokens: The "exp" (expiration) and "iat" (issued at) claims are timestamps. Caching: Cache expiration times. Scheduling: Cron jobs and task schedulers. Blockchain: Block timestamps in Bitcoin and Ethereum.

Seconds vs Milliseconds

Unix timestamps are traditionally in seconds (10 digits: 1700000000). However, JavaScript uses milliseconds (13 digits: 1700000000000). Many APIs use milliseconds too. Our converter auto-detects both — if the number has 13 digits, it's treated as milliseconds; if 10 digits, as seconds. Converted dates show your local timezone, so you always see the correct date and time for your location.

Common Timestamp Examples

0 = January 1, 1970 (Epoch). 86400 = January 2, 1970 (one day later). 1700000000 = November 14, 2023. Now = current timestamp. Timestamps make date math easy: adding 86400 (one day) moves exactly 24 hours forward regardless of timezones or daylight saving. This is why databases prefer timestamps over strings — they're unambiguous and efficient to compare.

Why Our Timestamp Converter is Different

Most online timestamp converters send your data to servers — a privacy concern if you're converting internal database timestamps or API data. Our converter runs entirely in your browser using JavaScript's Date object. Your timestamps never leave your computer. The converter auto-detects seconds vs milliseconds, shows both UTC and local time, and provides one-click copying of results.

The "Current Timestamp" button gets the exact Unix timestamp from your system clock. The date picker lets you select any date/time and convert it to a timestamp. Results show the full ISO string, local date/time, and UTC date/time. Perfect for developers debugging API responses, database administrators checking timestamps, or anyone working with time-based data. Free, unlimited, completely private. Try it now — enter any timestamp or select any date to see instant conversion.