Convert Unix timestamps to human-readable dates and vice versa. Auto-detects seconds/milliseconds, supports multiple date formats.
A Unix timestamp (Epoch Time) represents the number of seconds elapsed since January 1, 1970 00:00:00 UTC. It is widely used as the standard method for storing and transmitting date/time in operating systems, databases, and APIs.
A Unix timestamp is an integer representing the number of seconds elapsed since January 1, 1970 00:00:00 UTC (the "Unix Epoch"). It is timezone-independent and internationally standardized, making it the default time representation across virtually all technology stacks—operating systems, programming languages, databases, and more.
When designing APIs, date/time data is best transmitted as ISO 8601 strings or Unix timestamps (seconds or milliseconds). In JavaScript, Date.now() returns a millisecond timestamp, while Math.floor(Date.now()/1000) gives a second timestamp. Storing timestamps as integers in databases enables efficient indexing and range queries. Unix timestamps are essential in distributed systems for ensuring event ordering.
To convert a seconds timestamp to milliseconds, multiply by 1000; divide by 1000 for the reverse. In Python, use datetime.fromtimestamp() and datetime.timestamp(); in Java, use Instant.ofEpochSecond() and Instant.toEpochMilli(). The Year 2038 Problem occurs when a 32-bit signed integer reaches its maximum value (2,147,483,647) on January 19, 2038 at 03:14:07 UTC and overflows. 64-bit systems are unaffected.
Yes, they are the same. Both represent the number of seconds elapsed since January 1, 1970 00:00:00 UTC (the epoch). "Unix Time", "POSIX Time", and "Epoch Time" all refer to the same concept.
Typically, a 10-digit timestamp is in seconds and a 13-digit timestamp is in milliseconds. The current seconds timestamp is around 1.7 billion (10 digits), while milliseconds is around 1.7 trillion (13 digits). This converter auto-detects based on digit count.
Date.now() returns a millisecond timestamp. For seconds, use Math.floor(Date.now() / 1000). new Date().getTime() also returns a millisecond timestamp.
A negative timestamp represents a date before January 1, 1970. For example, -86400 represents December 31, 1969. Most systems support negative timestamps, but some legacy systems may have issues.
When a Unix timestamp stored as a 32-bit signed integer exceeds its maximum value of 2,147,483,647 (January 19, 2038 at 03:14:07 UTC), an overflow occurs. Modern 64-bit systems are not affected; legacy systems require upgrades.