Date and time formats

Date and time formats are specified using date and time pattern strings. Within date and time pattern strings, unquoted letters from A to Z and from a to z are interpreted as pattern letters. They represent the components of a date or time string. The text to include in the output should be quoted using single quotes (').

This table shows the pattern letters and how they are used:


Letter	Date or time component	Presentation	Examples
G	Era designator	Text	`AD`
`y`	Year	Year	`1996`; `96`
`Y`	Week year	Year	`2009`; `09`
`M`	Month in year	Month	`July`; `Jul`; `07`
`w`	Week in year	Number	`27`
`W`	Week in month	Number	`2`
`D`	Day in year	Number	`189`
`d`	Day in month	Number	`10`
`F`	Day of week in month	Number	`2`
`E`	Day name in week	Text	`Tuesday`; `Tue`
`u`	Day number of week (1 = Monday, ..., 7 = Sunday)	Text	`1`
`a`	AM/PM marker	Text	`PM`
`H`	Hour in day (0-23)	Number	`0`
`k`	Hour in day (1-24)	Number	`24`
`K`	Hour in AM/PM (0-11)	Number	`0`
`h`	Hour in AM/PM (1-12)	Number	`12`
`m`	Minute in hour	Number	`30`
`s`	Second in minute	Number	`55`
`S`	Millisecond	Number	`978`
`z`	Time zone	General time zone	`Pacific Standard Time`; `PST`; `GMT-08:00`
`Z`	Time zone	RFC 822 time zone	`-0800`
`X`	Time zone	ISO 8601 time zone	`-08`; `-0800`; `-08:00`

Pattern letters

The number of pattern letters determines the exact presentation.

Text: If the number of pattern letters is 4 or more, the full form is used. Otherwise, a short or abbreviated form is used if available.
Number: The number of pattern letters is the minimum number of digits, and shorter numbers are zero-padded to this amount.
Year: If the number of pattern letters is 2, the year is truncated to 2 digits. Otherwise it is interpreted as a number.
Month: If the number of pattern letters is 3 or more, the month is interpreted as text. Otherwise, it is interpreted as a number.
General time zone: Time zones are interpreted as text if they have names. For time zones that represent a GMT offset value, this syntax is used:
```
     GMTOffsetTimeZone:
             GMT  Sign  Hours  :  Minutes
     Sign: one of
             + -
     Hours:
             Digit
             Digit  Digit
     Minutes:
             Digit  Digit
     Digit: one of
             0 1 2 3 4 5 6 7 8 9
        
```
Hours must be between 0 and 23, and Minutes must be between 00 and 59. The format is locale independent and digits must be taken from the Basic Latin block of the Unicode standard.
For parsing, RFC 822 time zones are also accepted
RFC 822 time zone: For formatting, the RFC 822 4-digit time zone format is used:
```
     RFC822TimeZone:
             Sign  TwoDigitHours  Minutes
     TwoDigitHours:
             Digit Digit
```
TwoDigitHours must be between 00 and 23.