Timestamp Converter

Timestamp Converter is a free online tool that converts Unix timestamps to human-readable dates and times, and converts dates back to Unix timestamps. Enter any Unix timestamp in seconds or milliseconds and see the corresponding date, time, and time zone display instantly. Or select a date and time to get its Unix timestamp value. Results update in real time as you type — no button required.

A Unix timestamp (also called an epoch timestamp or POSIX timestamp) is the number of seconds that have elapsed since January 1, 1970 at 00:00:00 UTC — a reference point called the Unix epoch. The Unix epoch was chosen by the designers of the Unix operating system in the early 1970s as a convenient, unambiguous starting point. At the time of writing, the current Unix timestamp is approximately 1,700,000,000 — over 1.7 billion seconds have elapsed since the epoch.

Unix timestamps are ubiquitous in computing because they provide a single, unambiguous way to represent a moment in time regardless of timezone, calendar system, or locale. A timestamp like 1700000000 means the same exact moment everywhere in the world — there is no ambiguity about AM/PM notation, day/month order, timezone offset, or daylight saving time transitions. This makes timestamps the preferred format for storing and comparing times in databases, log files, event queues, API responses, and caches. Converting to human-readable dates is done only at the presentation layer.

The distinction between second-precision and millisecond-precision timestamps is important and a frequent source of bugs. JavaScript's Date.now() returns milliseconds since the epoch — a 13-digit number like 1700000000000. Most Unix-native environments (C, Python, Go, Linux system commands) return seconds — a 10-digit number like 1700000000. Passing a millisecond timestamp to code that expects seconds produces a date in the year 55000+. Passing a second timestamp to code expecting milliseconds produces a date in January 1970. Our converter auto-detects seconds vs milliseconds based on the number's magnitude and handles both correctly.

Log analysis is one of the most frequent uses for timestamp conversion. Server logs, application logs, database audit trails, and security event logs store times as Unix timestamps for storage efficiency and cross-timezone consistency. When investigating an incident or debugging a performance issue, converting log timestamps to local time makes it possible to correlate events with user reports and business events. Our converter displays timestamps in multiple time zones — UTC, your local browser time, and other common zones — simultaneously.

API integration developers convert timestamps when working with third-party APIs that return created_at, updated_at, expires_at, and similar fields as Unix timestamps. Frontend developers convert server-side timestamps to local time for display in user interfaces. Database administrators verify that record timestamps match expected business timelines. Security analysts convert event timestamps when investigating breaches and correlating events across systems with different clock configurations.

Timestamp Converter works entirely in your browser using JavaScript's Date object and Intl.DateTimeFormat API. Converting a timestamp to a date creates a new Date(timestamp * 1000) object and formats it with locale-aware display strings. Converting a date to a timestamp uses Date.parse() divided by 1000. Timezone conversions use the browser's built-in Intl API for accurate daylight saving time handling. No data is sent to any server.