The DateTimeImmutable and related classes allow you represent date/time information. The objects can be created by passing in a string presentation of date/time information, or from the current system's time.
A rich set of methods is supplied to modify and format this information as well, including handling timezones and DST transitions.
The date/time features in PHP implements the ISO 8601 calendar, which is a
» proleptic Gregorian
calendar which implements the current leap-day rules from before the
Gregorian calendar was in place, and also includes the year
0 as the year number in between -1
BCE and 1 CE. Leap seconds are not supported.
The date and time information is internally stored as a 64-bit number so all conceivably useful dates (including negative years) are supported. The range is from about 292 billion years in the past to the same in the future.
Note: The timezones referenced in this section can be found in the List of Supported Timezones.