It is really a good and small program, I began to like it as soon as I used it. Still, I have some suggestions for your reference:
1. Show up a small month date table of the current month above the calender items, dates with events are colored differently, so we could have a whole view of the month at a glance.
2. I have some repeated tasks and some tasks long in future, and I do not want to show them all at present. I hope we could have an option in task to show tasks xxx days ahead as you already have in done in calendar.

Anyway, it is a good program, thanks!