Okay. I just tested with other themes.
Was so used to Materia that I forgot about them.
Yeah an option would make sense then.
I'd like to look into this but that will probably take some time.

In D27939#624440, @mvourlakos wrote:

I think it is better to have an option for this in order to not be applied always when the user reverses the indicator..

And also are you sure that this way the growing circle animation of the indicator is still working correctly?

remove local variable "currentDate" and use "getDate" instead of "getDay"

Total overhaul of the patch.
I think I found the root cause for the events not being displayed.
I also inserted some if clauses to reduce calculations.
I also removed setting holidaysList.model = null as I could not reproduce the issue that was mentioned in the comment.

more simplifications

fix typos

only once set hasExpanded = true

This should even be lighter

Besides checking for isExpanded this prevents from updating the holidaysList twice by checking if the date needs to be reset.