When plans for a certain day change from what I previously scheduled during MHO, is it proper to change the calendar to match what the new day requires, or does that break a cardinal rule of MHO?

Example: My planned day has been disrupted due to 4 and 6 year olds unexpectedly being home and needing my care, so my initial plan for the day looks much different. Do I just “go with it” and NOT officially change on the calendar? Or do I take a few moments in the morning to update my calendar?