Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds, milliseconds, ISO 8601, and more.
About Timestamp Converter
Unix timestamps (also called Epoch time or POSIX time) represent a point in time as the number of seconds since January 1, 1970, 00:00:00 UTC -- a date known as the Unix Epoch. This simple integer representation makes timestamps ideal for storing, comparing, and calculating time differences in databases and applications. Unix timestamps are the universal time representation in computing because they are timezone-independent, unambiguous, easy to compare mathematically, and compact to store -- making them the preferred format for event logs, database records, and API communications.
Timestamp Formats Quick Reference
Seconds timestamps (10 digits) are used by Unix/Linux systems, PHP, Python, Ruby, and most backend languages. Milliseconds timestamps (13 digits) are used by JavaScript (Date.now()), Java (System.currentTimeMillis()), and many APIs. ISO 8601 (YYYY-MM-DDTHH:MM:SS.sssZ) is the international standard for human-readable date/time strings and is the recommended format for JSON APIs. RFC 2822 (e.g., "Tue, 01 Jan 2030 00:00:00 +0000") is used in email headers and HTTP date headers.
Important timestamp milestones: the Year 2038 Problem will occur on January 19, 2038, when 32-bit signed integer timestamps overflow (reaching 2,147,483,647). Systems using 32-bit timestamps must be upgraded to 64-bit before this date. JavaScript's Date object can represent dates from approximately 271,821 BC to 275,760 AD. For precise time tracking in distributed systems, consider NTP (Network Time Protocol) synchronization and monotonic clocks rather than wall clock timestamps, which can jump backward during clock adjustments.
Frequently Asked Questions
What is a Unix timestamp?
A Unix timestamp (also called Epoch time) is the number of seconds that have elapsed since January 1, 1970 00:00:00 UTC. It is widely used in programming to represent dates and times as a single number.
What is the difference between seconds and milliseconds timestamps?
A seconds timestamp has 10 digits (e.g., 1609459200), while a milliseconds timestamp has 13 digits (e.g., 1609459200000). JavaScript uses milliseconds, while Unix/PHP use seconds.
What is ISO 8601?
ISO 8601 is an international standard for date and time representation. The format is YYYY-MM-DDTHH:MM:SS.sssZ, where T separates date and time, and Z indicates UTC timezone.