The function expects to be given a string containing an English date format and will try to parse that format into a Unix timestamp (the number of seconds since January 1 1970 00:00:00 UTC), relative to the timestamp given in baseTimestamp, or the current time if baseTimestamp is not supplied.
The Unix timestamp that this function returns does not contain information about time zones. In order to do calculations with date/time information, you should use the more capable DateTimeImmutable.
Each parameter of this function uses the default time zone unless a time zone is specified in that parameter. Be careful not to use different time zones in each parameter unless that is intended. See date_default_timezone_get on the various ways to define the default time zone.
A date/time string. Valid formats are explained in Date and Time Formats.
The timestamp which is used as a base for the calculation of relative dates.
Returns a timestamp on success, false otherwise.
Exceptions and Errors
Every call to a date/time function will generate a E_WARNING if the time zone is not valid. See also date_default_timezone_set
If the number of the year is specified in a two digit format, the values between 00-69 are mapped to 2000-2069 and 70-99 to 1970-1999. See the notes below for possible differences on 32bit systems (possible dates might end on 2038-01-19 03:14:07).
The valid range of a timestamp is typically from Fri, 13 Dec 1901 20:45:54 UTC to Tue, 19 Jan 2038 03:14:07 UTC. (These are the dates that correspond to the minimum and maximum values for a 32-bit signed integer.)
For 64-bit versions of PHP, the valid range of a timestamp is effectively infinite, as 64 bits can represent approximately 293 billion years in either direction.
Dates in the m/d/y or d-m-y formats are disambiguated by looking at the separator between the various components: if the separator is a slash (/), then the American m/d/y is assumed; whereas if the separator is a dash (-) or a dot (.), then the European d-m-y format is assumed. If, however, the year is given in a two digit format and the separator is a dash (-), the date string is parsed as y-m-d.
To avoid potential ambiguity, it's best to use ISO 8601 (YYYY-MM-DD) dates or DateTime::createFromFormat when possible.
Using this function for mathematical operations is not advisable. It is better to use DateTime::add and DateTime::sub.
|8.0.0||baseTimestamp is nullable now.|