Tasks that MUST be done within a specific window in the future

And how to not see them before the start of that window.

Example
I have to make an important phone call on Dec 17th between 8AM and 12 PM. Currently, I have it deferred until 8, and due at 12. How do I remove this from my forecast view? Or am I approaching this wrong?

EDIT:
Solution - This should be on my calendar.