Alt-Drag to change the start time of dragged task and all future tasks simultaneously
Holding Alt (or any other key) when dragging a task on the calendar view should also drag all the tasks starting *after* it. This would offer a very easy way to slide your tasks in the future in those cases where you're behind schedule or when you need to quickly insert an urgent item in your fully timeblocked day.
If tasks overflow to the next day, they could default to the first hour of the "morning" (although maybe some users would prefer they simply extend past midnight).
The overflow to the previous day can be avoided if the Alt-Drag option is only available in day view (i.e. you can't really drag a task to yesterday this way, so no overflow edge case to solve).
Elegant way to address a nagging issue we've been mulling solutions for. I've submitted this along with "shift click to select multiple events" to our dev to-do list.