Translating day view into javascript, actually.

Summary: Ref T8300, Translating day view into javascript, actually

Test Plan: should be no user facing changes. should look the same as it did before.

Reviewers: Blessed Reviewers, epriestley

Reviewed By: Blessed Reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T8300

Differential Revision: https://secure.phabricator.com/D12985