Creating a "Checkable" Calendar

Hi there! I am trying to add switches, checkboxes, or radio buttons to my website. I have a monthly calendar, and I want my customers to be able to “check off” the date when they have completed a task, and have their progress saved for the next time they log in.

I was told by Wix Customer Support that Radio Buttons could handle this, but I am having no luck with adding them to my site. I would also need 30-31 buttons for each day of the month, so it’s becoming massively confusing.

Is there any way to do this? I have zero experience with code, so any language or assistance would be greatly appreciated. Thanks!