| Function | Description |
| checkdate() | Validates a Gregorian date |
| date_add() | Adds days, months, years, hours, minutes, and seconds to a date |
| date_create_from_format() | Returns a new DateTime object formatted according to a specified format |
| date_create() | Returns a new DateTime object |
| date_date_set() | Sets a new date |
| date_default_timezone_get() | Returns the default timezone used by all date/time functions |
| date_default_timezone_set() | Sets the default timezone used by all date/time functions |
| date_diff() | Returns the difference between two dates |
| date_format() | Returns a date formatted according to a specified format |
| date_get_last_errors() | Returns the warnings/errors found in a date string |
| date_interval_create_from_date_string() | Sets up a DateInterval from the relative parts of the string |
| date_interval_format() | Formats the interval |
| date_isodate_set() | Sets the ISO date |
| date_modify() | Modifies the timestamp |
| date_offset_get() | Returns the timezone offset |
| date_parse_from_format() | Returns an associative array with detailed info about a specified date, according to a specified format |
| date_parse() | Returns an associative array with detailed info about a specified date |
| date_sub() | Subtracts days, months, years, hours, minutes, and seconds from a date |
| date_sun_info() | Returns an array containing info about sunset/sunrise and twilight begin/end, for a specified day and location |
| date_sunrise() | Returns the sunrise time for a specified day and location |
| date_sunset() | Returns the sunset time for a specified day and location |
| date_time_set() | Sets the time |
| date_timestamp_get() | Returns the Unix timestamp |
| date_timestamp_set() | Sets the date and time based on a Unix timestamp |
| date_timezone_get() | Returns the time zone of the given DateTime object |
| date_timezone_set() | Sets the time zone for the DateTime object |
| date() | Formats a local date and time |
| getdate() | Returns date/time information of a timestamp or the current local date/time |
| gettimeofday() | Returns the current time |
| gmdate() | Formats a GMT/UTC date and time |
| gmmktime() | Returns the Unix timestamp for a GMT date |
| gmstrftime() | Formats a GMT/UTC date and time according to locale settings |
| idate() | Formats a local time/date as integer |
| localtime() | Returns the local time |
| microtime() | Returns the current Unix timestamp with microseconds |
| mktime() | Returns the Unix timestamp for a date |
| strftime() | Formats a local time and/or date according to locale settings |
| strptime() | Parses a time/date generated with strftime() |
| strtotime() | Parses an English textual datetime into a Unix timestamp |
| time() | Returns the current time as a Unix timestamp |
| timezone_abbreviations_list() | Returns an associative array containing dst, offset, and the timezone name |
| timezone_identifiers_list() | Returns an indexed array with all timezone identifiers |
| timezone_location_get() | Returns location information for a specified timezone |
| timezone_name_from_ abbr() | Returns the timezone name from abbreviation |
| timezone_name_get() | Returns the name of the timezone |
| timezone_offset_get() | Returns the timezone offset from GMT |
| timezone_open() | Creates new DateTimeZone object |
| timezone_transitions_get() | Returns all transitions for the timezone |
| timezone_version_get() | Returns the version of the timezone db |
