Date and Time

Times, Dates and Datetimes

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.^[1]

Following group of interfaces Date, Time and DateTime define addditional getters and modifiers to native PHP datetimes. These interfaces are implemented as immutable versions that use PHP's DateTimeImmutable instance as date data source.

• Time defines a time object with native DateTimeZone timezones
  • ImmutableTime is an immutable implementation of time
• Date defines a calendar date without time components
  • ImmutableDate is an immutable implementation of a calendar date
• DateTime defines a datetime
  • ImmutableDateTime is an immutable implementation of date and time

Times, Dates and Datetimes

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.^[1]

• Time defines a time object with native DateTimeZone timezones
  • ImmutableTime is an immutable implementation of time
• Date defines a calendar date without time components
  • ImmutableDate is an immutable implementation of a calendar date
• DateTime defines a datetime
  • ImmutableDateTime is an immutable implementation of date and time

Time-related data

ISO 8601 uses the 24-hour clock system. Either the seconds, or the minutes and seconds, may be omitted from the basic or extended time formats for greater brevity but decreased precision. ^[2]

Playground defines time in Time interface with representation of DateTimeZone timezones. Plain immutable time without dates is implemented in ImmutableTime class.

ISO Weeks and Months

An ISO week-numbering year (also called ISO year informally) has 52 or 53 full weeks. That is 364 or 371 days instead of the usual 365 or 366 days. The extra week is sometimes referred to as a leap week. ^[3]

A CalendarWeek implements a traversable seven day ISO week of a year.

• CalendarWeek::getIterator() return dates as Date instances.

Calendar units

CalendarUnit has two enumeration implementations. These Enumerations localize weekday and month names. Implemented calendar unit instances can translate its name to various language by using IntlDateFormatter.

The Weekday enumeration

Weekday enumeration is used to specify an association between a weekday name and a weekday number.

The Month enumeration

Month enumeration is used to specify an association between month name and a month number.

A CalendarMonth implements a traversable ISO month of a year.

• CalendarMonth::getIterator() return dates as Date instances.
• CalendarMonth::getWeeks() return correponding CalendarWeek instances.

CalendarMonth weeks as CalendarWeek instances.

• Weekday
• Month

Date Intervals

• Duration
• ImmutableDateInterval https://en.wikipedia.org/wiki/ISO_8601#Durations