The aligned day-of-week within a month.
The aligned day-of-week within a month.
This represents concept of the count of days within the period of a week
where the weeks are aligned to the start of the month.
This field is typically used with #ALIGNED_WEEK_OF_MONTH.
For example, in a calendar systems with a seven day week, the first aligned-week-of-month starts on day-of-month 1, the second aligned-week starts on day-of-month 8, and so on. Within each of these aligned-weeks, the days are numbered from 1 to 7 and returned as the value of this field. As such, day-of-month 1 to 7 will have aligned-day-of-week values from 1 to 7. And day-of-month 8 to 14 will repeat this with aligned-day-of-week values from 1 to 7.
Calendar systems that do not have a seven day week should typically implement this field in the same way, but using the alternate week length.
The aligned day-of-week within a year.
The aligned day-of-week within a year.
This represents concept of the count of days within the period of a week
where the weeks are aligned to the start of the year.
This field is typically used with #ALIGNED_WEEK_OF_YEAR.
For example, in a calendar systems with a seven day week, the first aligned-week-of-year starts on day-of-year 1, the second aligned-week starts on day-of-year 8, and so on. Within each of these aligned-weeks, the days are numbered from 1 to 7 and returned as the value of this field. As such, day-of-year 1 to 7 will have aligned-day-of-week values from 1 to 7. And day-of-year 8 to 14 will repeat this with aligned-day-of-week values from 1 to 7.
Calendar systems that do not have a seven day week should typically implement this field in the same way, but using the alternate week length.
The aligned week within a month.
The aligned week within a month.
This represents concept of the count of weeks within the period of a month
where the weeks are aligned to the start of the month.
This field is typically used with #ALIGNED_DAY_OF_WEEK_IN_MONTH.
For example, in a calendar systems with a seven day week, the first aligned-week-of-month starts on day-of-month 1, the second aligned-week starts on day-of-month 8, and so on. Thus, day-of-month values 1 to 7 are in aligned-week 1, while day-of-month values 8 to 14 are in aligned-week 2, and so on.
Calendar systems that do not have a seven day week should typically implement this field in the same way, but using the alternate week length.
The aligned week within a year.
The aligned week within a year.
This represents concept of the count of weeks within the period of a year
where the weeks are aligned to the start of the year.
This field is typically used with #ALIGNED_DAY_OF_WEEK_IN_YEAR.
For example, in a calendar systems with a seven day week, the first aligned-week-of-year starts on day-of-year 1, the second aligned-week starts on day-of-year 8, and so on. Thus, day-of-year values 1 to 7 are in aligned-week 1, while day-of-year values 8 to 14 are in aligned-week 2, and so on.
Calendar systems that do not have a seven day week should typically implement this field in the same way, but using the alternate week length.
The am-pm-of-day.
The am-pm-of-day.
This counts the AM/PM within the day, from 0 (AM) to 1 (PM). This field has the same meaning for all calendar systems.
The clock-hour-of-am-pm.
The clock-hour-of-am-pm.
This counts the hour within the AM/PM, from 1 to 12. This is the hour that would be observed on a standard 12-hour analog wall clock. This field has the same meaning for all calendar systems.
The clock-hour-of-day.
The clock-hour-of-day.
This counts the hour within the AM/PM, from 1 to 24. This is the hour that would be observed on a 24-hour analog wall clock. This field has the same meaning for all calendar systems.
The day-of-month.
The day-of-month.
This represents the concept of the day within the month. In the default ISO calendar system, this has values from 1 to 31 in most months. April, June, September, November have days from 1 to 30, while February has days from 1 to 28, or 29 in a leap year.
Non-ISO calendar systems should implement this field using the most recognized day-of-month values for users of the calendar system. Normally, this is a count of days from 1 to the length of the month.
The day-of-week, such as Tuesday.
The day-of-week, such as Tuesday.
This represents the standard concept of the day of the week.
In the default ISO calendar system, this has values from Monday (1) to Sunday (7).
The DayOfWeek class can be used to interpret the result.
Most non-ISO calendar systems also define a seven day week that aligns with ISO.
Those calendar systems must also use the same numbering system, from Monday (1) to
Sunday (7), which allows DayOfWeek to be used.
Calendar systems that do not have a standard seven day week should implement this field if they have a similar concept of named or numbered days within a period similar to a week. It is recommended that the numbering starts from 1.
The day-of-year.
The day-of-year.
This represents the concept of the day within the year. In the default ISO calendar system, this has values from 1 to 365 in standard years and 1 to 366 in leap years.
Non-ISO calendar systems should implement this field using the most recognized day-of-year values for users of the calendar system. Normally, this is a count of days from 1 to the length of the year.
The epoch-day, based on the Java epoch of 1970-01-01 (ISO).
The epoch-day, based on the Java epoch of 1970-01-01 (ISO).
This field is the sequential count of days where 1970-01-01 (ISO) is zero. Note that this uses the local time-line, ignoring offset and time-zone.
This field is strictly defined to have the same meaning in all calendar systems. This is necessary to ensure interoperability between calendars.
The era.
The era.
This represents the concept of the era, which is the largest division of the time-line.
This field is typically used with #YEAR_OF_ERA.
In the default ISO calendar system, there are two eras defined, 'BCE' and 'CE'.
The era 'CE' is the one currently in use and year-of-era runs from 1 to the maximum value.
The era 'BCE' is the previous era, and the year-of-era runs backwards.
See #YEAR_OF_ERA for a full example.
Non-ISO calendar systems should implement this field to define eras. The value of the era that was active on 1970-01-01 (ISO) must be assigned the value 1. Earlier eras must have sequentially smaller values. Later eras must have sequentially larger values,
The hour-of-am-pm.
The hour-of-am-pm.
This counts the hour within the AM/PM, from 0 to 11. This is the hour that would be observed on a standard 12-hour digital clock. This field has the same meaning for all calendar systems.
The hour-of-day.
The hour-of-day.
This counts the hour within the day, from 0 to 23. This is the hour that would be observed on a standard 24-hour digital clock. This field has the same meaning for all calendar systems.
The instant epoch-seconds.
The instant epoch-seconds.
This represents the concept of the sequential count of seconds where
1970-01-01T00:00Z (ISO) is zero.
This field may be used with #NANO_OF_DAY to represent the fraction of the day.
An Instant represents an instantaneous point on the time-line.
On their own they have no elements which allow a local date-time to be obtained.
Only when paired with an offset or time-zone can the local date or time be found.
This field allows the seconds part of the instant to be queried.
This field is strictly defined to have the same meaning in all calendar systems. This is necessary to ensure interoperation between calendars.
The micro-of-day.
The micro-of-day.
This counts the microsecond within the day, from 0 to (24 * 60 * 60 * 1,000,000) - 1. This field has the same meaning for all calendar systems.
This field is used to represent the micro-of-day handling any fraction of the second.
Implementations of TemporalAccessor should provide a value for this field if
they can return a value for #SECOND_OF_DAY filling unknown precision with zero.
When this field is used for setting a value, it should behave in the same way as
setting #NANO_OF_DAY with the value multiplied by 1,000.
The micro-of-second.
The micro-of-second.
This counts the microsecond within the second, from 0 to 999,999. This field has the same meaning for all calendar systems.
This field is used to represent the micro-of-second handling any fraction of the second.
Implementations of TemporalAccessor should provide a value for this field if
they can return a value for #SECOND_OF_MINUTE, #SECOND_OF_DAY or
#INSTANT_SECONDS filling unknown precision with zero.
When this field is used for setting a value, it should behave in the same way as
setting #NANO_OF_SECOND with the value multiplied by 1,000.
The milli-of-day.
The milli-of-day.
This counts the millisecond within the day, from 0 to (24 * 60 * 60 * 1,000) - 1. This field has the same meaning for all calendar systems.
This field is used to represent the milli-of-day handling any fraction of the second.
Implementations of TemporalAccessor should provide a value for this field if
they can return a value for #SECOND_OF_DAY filling unknown precision with zero.
When this field is used for setting a value, it should behave in the same way as
setting #NANO_OF_DAY with the value multiplied by 1,000,000.
The milli-of-second.
The milli-of-second.
This counts the millisecond within the second, from 0 to 999. This field has the same meaning for all calendar systems.
This field is used to represent the milli-of-second handling any fraction of the second.
Implementations of TemporalAccessor should provide a value for this field if
they can return a value for #SECOND_OF_MINUTE, #SECOND_OF_DAY or
#INSTANT_SECONDS filling unknown precision with zero.
When this field is used for setting a value, it should behave in the same way as
setting #NANO_OF_SECOND with the value multiplied by 1,000,000.
The minute-of-day.
The minute-of-day.
This counts the minute within the day, from 0 to (24 * 60) - 1. This field has the same meaning for all calendar systems.
The minute-of-hour.
The minute-of-hour.
This counts the minute within the hour, from 0 to 59. This field has the same meaning for all calendar systems.
The month-of-year, such as March.
The month-of-year, such as March.
This represents the concept of the month within the year. In the default ISO calendar system, this has values from January (1) to December (12).
Non-ISO calendar systems should implement this field using the most recognized month-of-year values for users of the calendar system. Normally, this is a count of months starting from 1.
The nano-of-day.
The nano-of-day.
This counts the nanosecond within the day, from 0 to (24 * 60 * 60 * 1,000,000,000) - 1. This field has the same meaning for all calendar systems.
This field is used to represent the nano-of-day handling any fraction of the second.
Implementations of TemporalAccessor should provide a value for this field if
they can return a value for #SECOND_OF_DAY filling unknown precision with zero.
The nano-of-second.
The nano-of-second.
This counts the nanosecond within the second, from 0 to 999,999,999. This field has the same meaning for all calendar systems.
This field is used to represent the nano-of-second handling any fraction of the second.
Implementations of TemporalAccessor should provide a value for this field if
they can return a value for #SECOND_OF_MINUTE, #SECOND_OF_DAY or
#INSTANT_SECONDS filling unknown precision with zero.
When this field is used for setting a value, it should set as much precision as the
object stores, using integer division to remove excess precision.
For example, if the TemporalAccessor stores time to millisecond precision,
then the nano-of-second must be divided by 1,000,000 before replacing the milli-of-second.
The offset from UTC/Greenwich.
The offset from UTC/Greenwich.
This represents the concept of the offset in seconds of local time from UTC/Greenwich.
A ZoneOffset represents the period of time that local time differs from UTC/Greenwich.
This is usually a fixed number of hours and minutes.
It is equivalent to the ZoneOffset#getTotalSeconds() total amount of the offset in seconds.
For example, during the winter Paris has an offset of +01:00, which is 3600 seconds.
This field is strictly defined to have the same meaning in all calendar systems. This is necessary to ensure interoperation between calendars.
The proleptic-month, which counts months sequentially from year 0.
The proleptic-month, which counts months sequentially from year 0.
The first month in year zero has the value zero. The value increase for later months and decrease for earlier ones. Note that this uses the local time-line, ignoring offset and time-zone.
This field is defined to have the same meaning in all calendar systems. It is simply a count of months from whatever the calendar defines as year 0.
The second-of-day.
The second-of-day.
This counts the second within the day, from 0 to (24 * 60 * 60) - 1. This field has the same meaning for all calendar systems.
The second-of-minute.
The second-of-minute.
This counts the second within the minute, from 0 to 59. This field has the same meaning for all calendar systems.
The proleptic year, such as 2012.
The proleptic year, such as 2012.
This represents the concept of the year, counting sequentially and using negative numbers.
The proleptic year is not interpreted in terms of the era.
See #YEAR_OF_ERA for an example showing the mapping from proleptic year to year-of-era.
The standard mental model for a date is based on three concepts - year, month and day.
These map onto the YEAR, MONTH_OF_YEAR and DAY_OF_MONTH fields.
Note that there is no reference to eras.
The full model for a date requires four concepts - era, year, month and day. These map onto
the ERA, YEAR_OF_ERA, MONTH_OF_YEAR and DAY_OF_MONTH fields.
Whether this field or YEAR_OF_ERA is used depends on which mental model is being used.
See ChronoLocalDate for more discussion on this topic.
Non-ISO calendar systems should implement this field as follows. If the calendar system has only two eras, before and after a fixed date, then the proleptic-year value must be the same as the year-of-era value for the later era, and increasingly negative for the earlier era. If the calendar system has more than two eras, then the proleptic-year value may be defined with any appropriate value, although defining it to be the same as ISO may be the best option.
The year within the era.
The year within the era.
This represents the concept of the year within the era.
This field is typically used with #ERA.
The standard mental model for a date is based on three concepts - year, month and day.
These map onto the YEAR, MONTH_OF_YEAR and DAY_OF_MONTH fields.
Note that there is no reference to eras.
The full model for a date requires four concepts - era, year, month and day. These map onto
the ERA, YEAR_OF_ERA, MONTH_OF_YEAR and DAY_OF_MONTH fields.
Whether this field or YEAR is used depends on which mental model is being used.
See ChronoLocalDate for more discussion on this topic.
In the default ISO calendar system, there are two eras defined, 'BCE' and 'CE'. The era 'CE' is the one currently in use and year-of-era runs from 1 to the maximum value. The era 'BCE' is the previous era, and the year-of-era runs backwards.
For example, subtracting a year each time yield the following:
- year-proleptic 2 = 'CE' year-of-era 2
- year-proleptic 1 = 'CE' year-of-era 1
- year-proleptic 0 = 'BCE' year-of-era 1
- year-proleptic -1 = 'BCE' year-of-era 2
Note that the ISO-8601 standard does not actually define eras. Note also that the ISO eras do not align with the well-known AD/BC eras due to the change between the Julian and Gregorian calendar systems.
Non-ISO calendar systems should implement this field using the most recognized year-of-era value for users of the calendar system. Since most calendar systems have only two eras, the year-of-era numbering approach will typically be the same as that used by the ISO calendar system. The year-of-era value should typically always be positive, however this is not required.
A standard set of fields.
This set of fields provide field-based access to manipulate a date, time or date-time. The standard set of fields can be extended by implementing
TemporalField.These fields are intended to be applicable in multiple calendar systems. For example, most non-ISO calendar systems define dates as a year, month and day, just with slightly different rules. The documentation of each field explains how it operates.
Specification for implementors
This is a final, immutable and thread-safe enum.