A standard set of fields. !(p) 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 {@link TemporalField}. !(p) 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.