🛠️ Time Tools
Unix Timestamp Convert
Displays current timestamp in real-time, supports conversion between timestamp and date (seconds/milliseconds), and automatically recognizes Beijing Time UTC+8.
What is a Unix Timestamp?
The Unix timestamp is the number of seconds (or milliseconds) that have elapsed since 1970-01-01 00:00:00 UTC (Unix Epoch), excluding leap seconds. It is a cross-platform, cross-language universal time representation widely used in database storage, API data exchange, logging, cache expiration, and other scenarios. A 10-digit number is usually in seconds, while a 13-digit number is usually in milliseconds.
What is the difference between seconds and milliseconds?
A second-level timestamp is a 10-digit integer (e.g., 1699999999), commonly used in Java/Go/C; a millisecond-level timestamp is a 13-digit integer (e.g., 1699999999000), defaulting to JavaScript and Java's System.currentTimeMillis(). This tool can automatically identify the digit count and switch, or you can manually select the "seconds/milliseconds" unit for precise conversion.
Why does the timestamp start from 1970?
1970-01-01 is the birthdate of the Unix operating system (Unix Epoch). Early Unix engineers chose this moment as the starting point for the system clock to represent time compactly using a 32-bit integer. This convention was adopted by the POSIX standard and is still in use. Note that the 32-bit second-level timestamp will overflow at 03:14:07 UTC on 2038-01-19 (the "Year 2038 problem"), and modern systems have generally switched to 64-bit.
How to handle time zones? How to calculate Beijing Time?
Timestamps themselves are based on UTC (Coordinated Universal Time), so the timestamp for the same moment is the same globally. Beijing Time is UTC+8, which is 8 hours added to UTC. This tool defaults to converting timestamps to Beijing Time for display, and outputs in various formats including ISO8601 and RFC1123 for easy copying.