Minor docs improvement suggestion:
The docs for DayOfWeekOptions say:
Number days from 1 if true and from 0 if false.
What day does the week start with (Monday=1, Sunday=7)
This might confuse some users into thinking that the meaning of week_start is dependent on the value of one_based_numbering. For example, some users might think that if they set one_based_numbering=0, then week_start=1 will be interpreted to mean Sunday instead of Monday.
Add a sentence in the docs explaining that the meaning of number passed to week_start is unaffected by the choice of one_based_numbering.