UTS- Date format patterns
http://unicode.org/reports/tr35/tr35-6.html#Date_Format_Patterns
Appendix F: Date Format Patterns
A date pattern is a string of characters, where specific strings of characters are replaced with date and time data from a calendar when formatting or used to generate data for a calendar when parsing. The following are the characters used in patterns to show the appropriate formats for a given locale. The following are examples:
| Pattern | Result (in a particular locale) |
|---|---|
| yyyy.MM.dd G 'at' HH:mm:ss zzz | 1996.07.10 AD at 15:08:56 PDT |
| EEE, MMM d, ''yy | Wed, July 10, '96 |
| h:mm a | 12:08 PM |
| hh 'o''clock' a, zzzz | 12 o'clock PM, Pacific Daylight Time |
| K:mm a, z | 0:00 PM, PST |
| yyyyy.MMMM.dd GGG hh:mm aaa | 01996.July.10 AD 12:08 PM |
Characters may be used multiple times. For example, if y is used for the year, 'yy' might produce '99', whereas 'yyyy' produces '1999'. For most numerical fields, the number of characters specifies the field width. For example, if h is the hour, 'h' might produce '5', but 'hh' produces '05'. For some characters, the count specifies whether an abbreviated or full form should be used, but may have other choices, as given below.
Two single quotes represents a literal single quote, either inside or outside single quotes. Text within single quotes is not interpreted in any way (except for two adjacent single quotes). Otherwise all ASCII letter from a to z and A to Z are reserved as syntax characters, and require quoting if they are to represent literal characters. In addition, certain ASCII punctuation characters may become variable in the future (eg ":" being interpreted as the time separator and '/' as a date separator, and replaced by respective locale-sensitive characters in display).
Note: the counter-intuitive use of 5 letters for the narrow form of weekdays and months is forced by backwards compatibility.
| Field | Sym. | No. | Example | Description | ||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| era | G | 1..3 | AD | Era - Replaced with the Era string for the current date. One to three letters for the abbreviated form, four letters for the long form, five for the narrow form. | ||||||||||||||||||||||||||||||||||||
| 4 | Anno Domini | |||||||||||||||||||||||||||||||||||||||
| 5 | A | |||||||||||||||||||||||||||||||||||||||
| year | y | 1..n | 1996 | Year. Normally the length specifies the padding, but for two letters it also specifies the maximum length. Example:
|
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| Y | 1..n | 1997 | Year (of "Week of Year"), used in ISO year-week calendar. May differ from calendar year. | |||||||||||||||||||||||||||||||||||||
| u | 1..n | 4601 | Extended year. This is a single number designating the year of this calendar system, encompassing all supra-year fields. For example, for the Julian calendar system, year numbers are positive, with an era of BCE or CE. An extended year value for the Julian calendar system assigns positive values to CE years and negative values to BCE years, with 1 BCE being year 0. | |||||||||||||||||||||||||||||||||||||
| quarter | Q | 1..2 | 02 | Quarter - Use one or two for the numerical quarter, three for the abbreviation, or four for the full name. | ||||||||||||||||||||||||||||||||||||
| 3 | Q2 | |||||||||||||||||||||||||||||||||||||||
| 4 | 2nd quarter | |||||||||||||||||||||||||||||||||||||||
| q | 1..2 | 02 | Stand-Alone Quarter - Use one or two for the numerical quarter, three for the abbreviation, or four for the full name. | |||||||||||||||||||||||||||||||||||||
| 3 | Q2 | |||||||||||||||||||||||||||||||||||||||
| 4 | 2nd quarter | |||||||||||||||||||||||||||||||||||||||
| month | M | 1..2 | 09 | Month - Use one or two for the numerical month, three for the abbreviation, or four for the full name, or five for the narrow name. | ||||||||||||||||||||||||||||||||||||
| 3 | Sept | |||||||||||||||||||||||||||||||||||||||
| 4 | September | |||||||||||||||||||||||||||||||||||||||
| 5 | S | |||||||||||||||||||||||||||||||||||||||
| L | 1..2 | 09 | Stand-Alone Month - Use one or two for the numerical month, three for the abbreviation, or four for the full name, or 5 for the narrow name. | |||||||||||||||||||||||||||||||||||||
| 3 | Sept | |||||||||||||||||||||||||||||||||||||||
| 4 | September | |||||||||||||||||||||||||||||||||||||||
| 5 | S | |||||||||||||||||||||||||||||||||||||||
| week | w | 1..2 | 27 | Week of Year. | ||||||||||||||||||||||||||||||||||||
| W | 1 | 3 | Week of Month | |||||||||||||||||||||||||||||||||||||
| day | d | 1..2 | 1 | Date - Day of the month | ||||||||||||||||||||||||||||||||||||
| D | 1..3 | 345 | Day of year | |||||||||||||||||||||||||||||||||||||
| F | 1 | 2 |
Day of Week in Month. The example is for the 2nd Wed in July | |||||||||||||||||||||||||||||||||||||
| g | 1..n | 2451334 | Modified Julian day. This is different from the conventional Julian day number in two regards. First, it demarcates days at local zone midnight, rather than noon GMT. Second, it is a local number; that is, it depends on the local time zone. It can be thought of as a single number that encompasses all the date-related fields. | |||||||||||||||||||||||||||||||||||||
| week day |
E | 1..3 | Tues | Day of week - Use one through three letters for the short day, or four for the full name, or five for the narrow name. | ||||||||||||||||||||||||||||||||||||
| 4 | Tuesday | |||||||||||||||||||||||||||||||||||||||
| 5 | T | |||||||||||||||||||||||||||||||||||||||
| e | 1..2 | 2 | Local day of week. Same as E except adds a numeric value that will depend on the local starting day of the week, using one or two letters. For this example, Monday is the first day of the week. | |||||||||||||||||||||||||||||||||||||
| 3 | Tues | |||||||||||||||||||||||||||||||||||||||
| 4 | Tuesday | |||||||||||||||||||||||||||||||||||||||
| 5 | T | |||||||||||||||||||||||||||||||||||||||
| c | 1 | 2 | Stand-Alone local day of week - Use one letter for the local numeric value (same as 'e'), three for the short day, or four for the full name, or five for the narrow name. | |||||||||||||||||||||||||||||||||||||
| 3 | Tues | |||||||||||||||||||||||||||||||||||||||
| 4 | Tuesday | |||||||||||||||||||||||||||||||||||||||
| 5 | T | |||||||||||||||||||||||||||||||||||||||
| period | a | 1 | AM | AM or PM | ||||||||||||||||||||||||||||||||||||
| hour | h | 1..2 | 11 | Hour [1-12]. | ||||||||||||||||||||||||||||||||||||
| H | 1..2 | 13 | Hour [0-23]. | |||||||||||||||||||||||||||||||||||||
| K | 1..2 | 0 | Hour [0-11]. | |||||||||||||||||||||||||||||||||||||
| k | 1..2 | 24 | Hour [1-24]. | |||||||||||||||||||||||||||||||||||||
| minute | m | 1..2 | 59 | Minute. Use one or two for zero padding. | ||||||||||||||||||||||||||||||||||||
| second | s | 1..2 | 12 | Second. Use one or two for zero padding. | ||||||||||||||||||||||||||||||||||||
| S | 1..n | 3457 | Fractional Second - rounds to the count of letters. (example is for 12.34567) | |||||||||||||||||||||||||||||||||||||
| A | 1..n | 69540000 | Milliseconds in day. This field behaves exactly like a composite of all time-related fields, not including the zone fields. As such, it also reflects discontinuities of those fields on DST transition days. On a day of DST onset, it will jump forward. On a day of DST cessation, it will jump backward. This reflects the fact that is must be combined with the offset field to obtain a unique local time value. | |||||||||||||||||||||||||||||||||||||
| zone | z | 1..3 | PDT | Timezone - Use one to three letters for the short timezone or four for the full name. For more information, see Appendix J: Time Zone Display Names | ||||||||||||||||||||||||||||||||||||
| 4 | Pacific Daylight Time | |||||||||||||||||||||||||||||||||||||||
| Z | 1..3 | -0800 | Use one to three letters for RFC 822, four letters for GMT format. | |||||||||||||||||||||||||||||||||||||
| 4 | GMT-08:00 | |||||||||||||||||||||||||||||||||||||||
| v | 1 | PT | Use one letter for short wall (generic) time, four for long wall time. For more information, see Appendix J: Time Zone Display Names | |||||||||||||||||||||||||||||||||||||
| 4 | Pacific Time |
All non-letter character represent themselves in a pattern, except for the single quote. It is used to 'escape' letters. Two single quotes in a row, whether inside or outside a quoted sequence, represent a 'real' single quote.
F.1 Localized Pattern Characters (deprecated)
These are characters that can be used when displaying a date pattern to an end user. This can occur, for example, when a spreadsheet allows users to specify date patterns. Whatever is in the string is substituted one-for-one with the characters "GyMdkHmsSEDFwWahKzYe", with the above meanings. Thus, for example, if "J" is to be used instead of "Y" to mean Year, then the string would be: "GyMdkHmsSEDFwWahKzJe".
This element is deprecated. It is recommended instead that a more sophisticated UI be used for localization, such as using icons to represent the different formats (and lengths) in the Date Field Symbol Table.
F.2 AM / PM
Even for countries where the customary date format only has a 24 hour format, both the am and pm localized strings must be present and must be distinct from one another. Note that as long as the 24 hour format is used, these strings will normally never be used, but for testing and unusual circumstances they must be present.
F.3 Eras
There are only two values for an era in a Gregorian calendar, "BC" and "AD". These values can be translated into other languages, like "a.C." and and "d.C." for Spanish, but there are no other eras in the Gregorian calendar. Other calendars have a different numbers of eras. Care should be taken when translating the era names for a specific calendar.
F.4 Week of Year
Values calculated for the Week of Year field range from 1 to 53 for the Gregorian calendar (they may have different ranges for other calendars). Week 1 for a year is the first week that contains at least the specified minimum number of days from that year. Weeks between week 1 of one year and week 1 of the following year are numbered sequentially from 2 to 52 or 53 (if needed). For example, January 1, 1998 was a Thursday. If the first day of the week is MONDAY and the minimum days in a week is 4 (these are the values reflecting ISO 8601 and many national standards), then week 1 of 1998 starts on December 29, 1997, and ends on January 4, 1998. However, if the first day of the week is SUNDAY, then week 1 of 1998 starts on January 4, 1998, and ends on January 10, 1998. The first three days of 1998 are then part of week 53 of 1997.
Values are similarly calculated for the Week of Month.
F.5 Week Elements
- firstDay
- A number indicating which day of the week is considered the 'first' day, for calendar purposes. Because the ordering of days may vary between calendar, keywords are used for this value, such as sun, mon,... These values will be replaced by the localized name when they are actually used.
- minDays (Minimal Days in First Week)
- Minimal days required in the first week of a month or year. For example, if the first week is defined as one that contains at least one day, this value will be 1. If it must contain a full seven days before it counts as the first week, then the value would be 7.
- weekendStart, weekendEnd
- Indicates the day and time that the weekend starts or ends. As with firstDay, keywords are used instead of numbers.
