Calendar jumps around every time I open the indicator

[jlnr]

What Happened?

Every time I open the indicator, I can see the days jump around from what looks like an "off by one" position.

This happens no matter if my week is set to start on Monday or Sunday. (Although it is also not quite clear to me how to change this setting.)

https://github.com/elementary/wingpanel-indicator-datetime/assets/70772/67919b90-2f70-4410-8ab8-924e8eeba98b

Steps to Reproduce

1. Click the date/time indicator.

Expected Behavior

The calendar shows the correct layout right from the start of the fade-in animation.

OS Version

7.x (Horus)

Software Version

Latest release (I have run all updates)

Log Output

No response

Hardware Info

elementary Daily ISO 2023-09-07 on a MacBook Pro, but also happens on my other computer.