v1.4.0
- Add
DayOfWeek(ISO-8601 weekday enum) andTimeOfDay(HH:MM value object) with corresponding tests and README documentation. - Refactor
Durationto use an internalSecondsvalue object, introduceInvalidSeconds, adddivide(), and switch tofrom*()factories +toSeconds()accessor. - Rename
Period::of()toPeriod::from()and update usages across tests and README.