how to select a date with a color
Unfortunately this extension doesn't have much options.
Though if you want to highlight a date, you should check SetDate method.
I already use your calendar extension, so how to enter the data from tinydb into the calendar? this example.
This is a calendar view extension. It is not a "full calendar" that accepts events. You will have to, as I suggested in a different topic on the same subject, store your events in lists, and reference them from the selected date of this calendar view extension.