I feel instead of those huge add event buttons which do not complement the Home Screen u should add the floating button from application. And since it’s interactive a one click would create in your default and a tap and hold would allow you to choose which calendar to add.

This would also give the option to show more events which are more important than those oversized buttons.

Also I feel the down arrow should advance the date forward not backward.

Is there a way to jump back to todays date on widget quickly?