0000 may refer to:
*the
year 10,000 problem
*a null
train reporting number
A train reporting number in Great Britain identifies a particular train service. It consists of:
* A single-digit number, indicating the class (type) of train, followed by
* A letter, indicating the destination area, followed by
* A two-digi ...
or headcode
*a suffix to a time indicating
Coordinated Universal Time
Coordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about one second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently use ...
, rather than a local time zone
*the
null character
The null character (also null terminator) is a control character with the value zero.
It is present in many character sets, including those defined by the Baudot and ITA2 codes, ISO/IEC 646 (or ASCII), the C0 control code, the Universal Coded Ch ...
*
Midnight in
24-hour clock
{{number disambiguation