Is this sentence OK?
There is a change of plan. I would like to take my off day on November 1st instead of November 4th.
Seems okay to me.
Or "There has been a change of plan" or "I've had a change in plans."
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.