Your Calendar Is a Budget, Not a Diary
Money gets a budget; time gets a record of whatever happened to it. Run the week like the scarce resource it is.
Most calendars are written by other people. Meetings land on them the way expenses land on an unbudgeted account — first come, first served, until the balance is gone and the things you said mattered most are left unfunded.
A budget works because it allocates before the month begins. Do the same with the week: block the deep work, the family dinner, the run, before Monday opens the floodgates. What is pre-committed is defensible. What is open is gone.