The term "Period" derives from early versions of ISO-8601. You will note that the standard ISO-8601 format for Period is P1Y2M3D, where the "P" stands for "Period".
The spec has changed over time. The original 1998 version [1] is where Joda-Time, and thus Java-Time derive their names. The 2016 version [2] has different terminology. * Period - a descriptive quantity of time based on fields (from years to seconds in Joda-Time, from years to days in Java-Time) * Duration - a precise quantity of time based on seconds * Interval - a section of the time-line specified by the start and end instants (not in Java-Time ATM) Stephen [1] https://www.webaugur.com/bibliotheca/standards/iso8601/8601.pdf [2] https://www.loc.gov/standards/datetime/iso-tc154-wg5_n0038_iso_wd_8601-1_2016-02-16.pdf On Wed, 18 Jun 2025 at 18:54, Archie Cobbs <archie.co...@gmail.com> wrote: > > Period is like Duration - they are both "lengths of time", just using > different units (so they are both a TemporalAmount). > > Similar to how LocalDateTime vs. Instant are both "points in time", just > using different units (so they are both a Temporal). > > But you bring up a good point - perhaps CalendarDuration would have been a > better name than Period... > > -Archie > > On Wed, Jun 18, 2025 at 12:24 PM Pavel Rappo <pavel.ra...@gmail.com> wrote: >> >> We are talking about a period, not an interval. I used the word >> "interval" in my previous email in the sense close to that def. #5 >> from your dictionary link: >> >> > : a set of real numbers between two numbers either including or excluding >> > one or both of them >> >> So to me, an interval between two dates logically consists of all >> (time) instants between its both ends. >> >> Alright, your reply kinda tips the scales in favour of "it's just me". >> Perhaps others don't have a similar issue with java.util.Period. > > > -- > Archie L. Cobbs
