When creating a new event you can choose which category it is. If you want to classify it as a category that doesn't yet exist, you can't.
Steps to reproduce:
- Click on a day.
- Create an event.
- Click on the different options for categories.
Actual results:
You can select one of the already existing categories or none.
Expected results:
You can select one of the already existing categories, but you also have the option to create a new category to which you can assign the event.