* Access to date and time using fields and units, and date time adjusters. *
** This package expands on the base package to provide additional functionality for more powerful use cases. Support is * included for: *
** Dates and times are expressed in terms of fields and units. A unit is used to measure an amount of time, such as * years, days or minutes. All units implement {@link java.time.temporal.TemporalUnit}. The set of well known units is * defined in {@link java.time.temporal.ChronoUnit}, such as {@code DAYS}. The unit interface is designed to allow * application defined units. *
** A field is used to express part of a larger date-time, such as year, month-of-year or second-of-minute. All fields * implement {@link java.time.temporal.TemporalField}. The set of well known fields are defined in * {@link java.time.temporal.ChronoField}, such as {@code HOUR_OF_DAY}. Additional fields are defined by * {@link java.time.temporal.JulianFields}, {@link java.time.temporal.WeekFields} and * {@link java.time.temporal.IsoFields}. The field interface is designed to allow application defined fields. *
** This package provides tools that allow the units and fields of date and time to be accessed in a general way most * suited for frameworks. {@link java.time.temporal.Temporal} provides the abstraction for date time types that support * fields. Its methods support getting the value of a field, creating a new date time with the value of a field * modified, and querying for additional information, typically used to extract the offset or time-zone. *
** One use of fields in application code is to retrieve fields for which there is no convenience method. For example, * getting the day-of-month is common enough that there is a method on {@code LocalDate} called {@code getDayOfMonth()}. * However for more unusual fields it is necessary to use the field. For example, * {@code date.get(ChronoField.ALIGNED_WEEK_OF_MONTH)}. The fields also provide access to the range of valid values. *
* ** A key part of the date-time problem space is adjusting a date to a new, related value, such as the "last day of the * month", or "next Wednesday". These are modeled as functions that adjust a base date-time. The functions implement * {@link java.time.temporal.TemporalAdjuster} and operate on {@code Temporal}. A set of common functions are provided * in {@link java.time.temporal.TemporalAdjusters}. For example, to find the first occurrence of a day-of-week after a * given date, use {@link java.time.temporal.TemporalAdjusters#next(java.time.DayOfWeek)}, such as * {@code date.with(next(MONDAY))}. Applications can also define adjusters by implementing * {@link java.time.temporal.TemporalAdjuster}. *
** The {@link java.time.temporal.TemporalAmount} interface models amounts of relative time. *
** In addition to adjusting a date-time, an interface is provided to enable querying via * {@link java.time.temporal.TemporalQuery}. The most common implementations of the query interface are method * references. The {@code from(TemporalAccessor)} methods on major classes can all be used, such as * {@code LocalDate::from} or {@code Month::from}. Further implementations are provided in * {@link java.time.temporal.TemporalQueries} as static methods. Applications can also define queries by implementing * {@link java.time.temporal.TemporalQuery}. *
* ** Different locales have different definitions of the week. For example, in Europe the week typically starts on a * Monday, while in the US it starts on a Sunday. The {@link java.time.temporal.WeekFields} class models this * distinction. *
** The ISO calendar system defines an additional week-based division of years. This defines a year based on whole Monday * to Monday weeks. This is modeled in {@link java.time.temporal.IsoFields}. *
* ** The Javadoc "@param" definition is used to summarise the null-behavior. *
*/ @ej.annotation.NonNullByDefault package java.time.temporal;