When you click on a day in the calendar, but not on any of the events, a semi-transparent widget will appear that allows you to (attempt to) add a new event - click the plus sign. Or something. I haven't fully worked out the interaction model here. Feedback welcome. Usual disclaimers about color and this just being a layout test.
For anyone who cares, I'll create a master sheet after we've worked out the kinks on all the pages that share the same template. This master sheet will lock in default proportions, etc.