The phrase "activities of the day" refers to all the things you plan or have to do during the day. It includes tasks, chores, events, or anything else that you need to accomplish within that particular day. Full definition
This was our last activity of the day and time was given for the divers to rest. (aggressor.com)
A daycare director is a person who is responsible for handling all the day to day activities of a day care and ensuring the fact that all the activities are smoothly run and managed. (sampleresumeobjectives.org)
We didn't know it that first day, but it was soon to become one of our most favorite activities of the day. (viktoriastable.com)