Calendar shouldn't follow dates under the mouse when "dragging" over dates

When dragging the mouse over the calendar and a date from a previous month is hit, it will change the visible month to that month. This becomes worse when dragging the mouse between in the start/end of the calendar, because there are usually several days shown from the previous month, and the calendar quickly goes back several months.

Instead, it should probably only follow dates in the previous/next month on mouse release instead of press.