The calendarId accessor property of Temporal.PlainMonthDay instances returns a string representing the calendar used to interpret the internal ISO 8601 date.

The monthCode accessor property of Temporal.PlainDateTime instances returns a calendar-specific string representing the month of this date. It is calendar-dependent.

The since() method of Temporal.ZonedDateTime instances returns a new Temporal.Duration object representing the duration from another date-time (in a form convertible by Temporal.ZonedDateTime.from()) to this date-time. The duration is positive if the other date-time is before this date-time, and negative if after.

The withCalendar() method of Temporal.PlainDateTime instances returns a new Temporal.PlainDateTime object representing this date-time interpreted in the new calendar system. Because all Temporal objects are designed to be immutable, this method essentially functions as the setter for the date-time's calendarId property.

The toPlainDateTime() method of Temporal.PlainDate instances returns a new Temporal.PlainDateTime object representing this date and a supplied time in the same calendar system.

The millisecond accessor property of Temporal.PlainTime instances returns an integer from 0 to 999 representing the millisecond (10-3 second) component of this time.

The yearOfWeek accessor property of Temporal.PlainDate instances returns an integer representing the year to be paired with the weekOfYear of this date, or undefined if the calendar does not have a well-defined week system. It is calendar-dependent.

The toLocaleString() method of Temporal.Instant instances returns a string with a language-sensitive representation of this instant. In implementations with Intl.DateTimeFormat API support, this method delegates to Intl.DateTimeFormat.

The daysInWeek accessor property of Temporal.ZonedDateTime instances returns a positive integer representing the number of days in the week of this date. It is calendar-dependent.

The daysInWeek accessor property of Temporal.PlainDateTime instances returns a positive integer representing the number of days in the week of this date. It is calendar-dependent.