If you are wondering the worst way to spend a day, it is this... okay, this might be a slight exaggeration, I can think of various torture rituals that would surely be worse... but I will certainly be haunted for weeks to come.
1. Take 15 excited kids who have eaten valentine chocolate for breakfast.
2. Put said children on a bus.
3. Add 5 adults who wish to make conversation despite the roaring din of 15 children.
4. Stay on bus for 2 hours.
5. Arrive at destination and stay for two hours.
6. Potty 15 children.
7. Put them back on the bus.
8. Ride again for 2 hours.
9. Do the math. You have just spent 4 out of 6 hours on a bus with 15 five and six-year olds.
10. Arrive back at school in time to pack them all up and send them home. (That's the good part.)
Sound fun?