Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates instantly. Supports both seconds and milliseconds, auto-detection, ISO 8601 output, and a live-updating current timestamp display.
Timestamp → Date
Date → Timestamp
How to Use This Calculator
- Current Timestamp: The live timestamp at the top updates every second, showing the current time in both seconds and milliseconds.
- Timestamp to Date: Paste any Unix timestamp (in seconds or milliseconds) and click "Convert to Date" to see the human-readable date in multiple formats.
- Date to Timestamp: Pick a date and time using the date picker, then click "Convert to Timestamp" to get the Unix timestamp in seconds and milliseconds.
Formula
Milliseconds to Date: date = new Date(timestamp)
Date to Seconds: timestamp = Math.floor(date.getTime() / 1000)
A Unix timestamp is the number of seconds that have elapsed since January 1, 1970 00:00:00 UTC (the Unix epoch). Timestamps with 10 digits are in seconds; 13 digits indicate milliseconds.
Examples
1700000000 → November 14, 2023 22:13:20 UTC (10 digits = seconds)
1700000000000 → Same date, but in milliseconds (13 digits). Many APIs (e.g., JavaScript Date.now()) return milliseconds.
0 → January 1, 1970 00:00:00 UTC. This is the start of the Unix epoch, used as the baseline for all timestamp calculations.
Frequently Asked Questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds that have elapsed since January 1, 1970 00:00:00 UTC, known as the Unix epoch. It is widely used in computing, databases, and APIs because it provides a timezone-independent, machine-readable representation of date and time.
How many digits is a Unix timestamp (seconds vs milliseconds)?
A Unix timestamp in seconds has 10 digits (e.g., 1700000000). A timestamp in milliseconds has 13 digits (e.g., 1700000000000). This tool auto-detects the format based on digit count.
What is the Unix epoch?
The Unix epoch is January 1, 1970 00:00:00 UTC. It is the starting point from which all Unix timestamps are measured. The choice of this date is historical and tied to the development of the Unix operating system at Bell Labs.
How to convert a timestamp to a date?
To convert a Unix timestamp (in seconds) to a date, multiply by 1000 to convert to milliseconds, then create a JavaScript Date object: new Date(timestamp * 1000). For milliseconds, use new Date(timestamp) directly. This tool does the conversion for you.