Holidays generated do not reflect their indicated date

[jaraco]

When rendering a calendar, it would be useful for the calendar to reflect the indicated date for each holiday. For example, "New year" happens on "the first day in January" or "January 1st". That's pretty simple, but other holidays have a more complicated indication, such as "Martin Luther King, Jr. Day" which is indicated on the "3rd Monday in January". These indications are useful for someone reading the calendar to know what indicated that date.

[jaraco]

For this issue and the prior two, I have an approach that I've used in a similar project which I find works much better for allowing a calendar to represent its holidays. I'll be putting together a pull request with a draft.

[jaraco]

If you desire this feature, consider the calendra fork.