Q: What is the Unix epoch and why was it chosen?
The Unix epoch is January 1, 1970, 00:00:00 UTC. It was chosen as a convenient reference point when the Unix operating system was being developed in the early 1970s. All Unix timestamps count the number of seconds (or milliseconds) that have elapsed since this moment, providing a simple, universal way to represent time across different systems and timezones.
Q: What is the difference between seconds and milliseconds timestamps?
Unix timestamps in seconds are 10 digits (e.g., 1625097600), while millisecond timestamps are 13 digits (e.g., 1625097600000). JavaScript's Date.now() returns milliseconds, while many server-side languages use seconds by default.
Q: What timezone does the converter use?
Unix timestamps are always in UTC. The converter displays results in your local timezone by default and also shows UTC and ISO 8601 formats. You can use the timezone selector to view the time in any timezone.
Q: What is the Year 2038 problem?
32-bit systems store Unix timestamps as a signed 32-bit integer, which will overflow on January 19, 2038. Modern 64-bit systems use 64-bit integers, extending the range far beyond any practical concern.
Q: How do I convert a JavaScript Date.now() value?
JavaScript's Date.now() returns a timestamp in milliseconds. Paste it into the input field and select "Milliseconds" as the format. The converter will display the corresponding human-readable date in your chosen format.