calendar storage

I am looking for a calendar storage solution that will work as a desktop application. It is not yet essential for the calendar to sync with other devices or accounts, but that is something I may explore in the future. Specifically, I'm looking for something that has task management capabilities. My business is expanding and I need an efficient calendar solution to manage all of my tasks and commitments. tabs or dashboard should be: data entry, search/sort form, report and calendar (this may be subject to change i guess)