Some programs have a small dark blue or black circle with white text that indicates the number of events on that day. This is a very nice symbol that makes it easy to read. and it is understood what the symbol stands for. A single number with nothing else with it can be mistook for something else.
You have an event counter on the week view, and it works great. But it is light in color. It may make it easier to read if you adopted something similar to the above.
Also it would be nice to have the event counter display on the Day view as well.