Overview#

Unix Time (also known as POSIX time) is a system for describing instants in time, defined as the number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970 not counting leap seconds. (ie the Unix Epoch)Unix Time is a DateTime and a NumericDate

Unix Time is used widely in UNIX-like and many other Operating Systems and file formats. Because it does not handle leap seconds, it is neither a linear representation of time nor a true representation of UTC.

Unix Time may be checked on most UNIX Operating Systems by typing date +%s on the command-line.

Unix Time Overflow #

At 03:14:08 UTC on January 19, 2038 (+231), a 32-bit Signed int representation of Unix time will overflow. Systems using a 32-bit signed integer Unix Time will therefore be unable to represent that time, or any later, and will likely wrap around to 20:45:52 UTC on December 13, 1901, with integer value -231. This is a NumericDate!! More Information There might be more information for this subject on one of the following:

• DirXML Code Snippets
• Identity Token Claims
• Microsoft TIME
• POSIX time
• Time And Epochs
• Time-based One-time Password Algorithm
• Token Introspection Endpoint