How can I create a database to keep my visits and reports organised?

Hey guys, I work for a local authority and my job consists of going out to visit people and then writing reports on them.

The markers I need are

A visit to be completed every 50 days (that gives 6 days grace)

A big document to be completed every 165 days (that gives 15 days grace)

I’m sure there’s an easy formula where I can visually colour coded see when someone is coming up for a visit or a big document that is needed to be updated so I can easily keep track of my reports and visits? Thanks