[BUG] Calendar - month view does not fill the entire space

[v-marinkov]

What set up are you using
Self Hosted 3.0.6 on Docker

The problem
The month view in the calendar does not fill the entire space of the widget:

The day and list views, on the other hand, work correctly:

This bug together with these two calendar improvements would take the time-blocking functionality to a much more polished level: #2316, #2332, and #2334