A full day and a good day are not always the same thing. Give your plans a shape that leaves room for the place itself.
Choose one anchor
Pick the visit or experience that matters most. Put it on the map and note any fixed entry time. Everything else should support that choice rather than compete with it. If there are two essential visits far apart, consider using different days.
Count the invisible time
Leaving a room, finding an entrance, waiting, eating, and getting your bearings all take time. A route made only of travel estimates and attraction durations will usually feel tight. Add space between commitments so small delays do not spoil the mood.
Keep one optional stop
Save an extra place near your main route, but label it as optional. It is there if you finish early and feel curious. Skipping it should not feel like failing the day; that freedom is the point.
Decide when the day is done
Choose a comfortable finish near dinner or your accommodation. You can always walk a little more if you feel good. Ending with energy left often makes the following morning more enjoyable than squeezing in one last distant sight.