relative to which anchor date?
a calendar composed of multiple calendars.
list of calendars
period start date inclusive
period end date inclusive
build period based on schedule start / end date and period end days
for each PositionOfMonth implementation Lamma expect there is one and only one day match the criteria
for each PositionOfYear implementation Lamma expect there is one and only one day match the criteria in each year
once we shifted, how we are going to select the date to use
how we are going to shift relative to the anchor date
build periods based on stub rules
all operations requiring java.
Entry point of the library
frequency is used to generate recurrence dates
consider all weekend as holiday