Possible fix for month view day deadzone

Summary: Ref T8193, Possible fix for month view day deadzone

Test Plan: Open Calendar month view in Chrome, Firefox, or Safari. Verify that days with many events still link to the day views of those days.

Reviewers: chad, epriestley, Blessed Reviewers

Reviewed By: epriestley, Blessed Reviewers

Subscribers: Korvin, epriestley

Maniphest Tasks: T8193

Differential Revision: https://secure.phabricator.com/D12969