update -

i don't have to work saturdays after all. the new hours were for teachers who had not already signed contracts.

in fact, i come out on top because with saturdays, the weekday school schedule is going to be about 45 minutes shorter.

therefore i work less, and he said already-contracted teachers will still be paid the same, even with 5 hours less work per week.

as well, we get the option of working saturdays if we want extra money. which i do.

so...

life is generally quite sweet.