I would be upset also. I know that in our school district we have a K-4,5th & 6th, 7th & 8th, and then high school buildings and many parent have chilldren in all four buildings at the same time. Our PTA council for our school district sets the dates for our meetings and then it is up to each school to set up the times. Here is how it goes in our council standing rules. The 5th & 6th building meet on the 1st Tuesday of the month, K-4 on the 2nd Tuesday, 7th & 8th meet on the 3rd Tuesday, and council meetings our on the 4th Tuesday. Because when they get in high school there are usually booster groups that support each activity I believe the meet less often and they probably set the times up and put on the calendar. I am pretty sure that the bylaws probably would not let just one person to make the change in the date. I would think that the executive board (which includes all committee chairpersons and the elected board) would have to vote on this change and the majority would have to agee to change the date.
Maybe the rules weren't followed and it is possible that the person who changed the date doesn't know they are breaking the rules.

MS

I like the BTW. I think that is important. Most importantly, alot of our parents (me included) work nights sometimes, and I have to give notice. So I have a night off I could have been working. Now, I agree somethings have to change because the schedule is made so far in advance.

Sometimes meetings need to change and sometimes those changes cause conflicts - that's just the way life is. Hopefully, the meetings are changed for good reason - IMHO, the PTO Pres. having an unavoidable conflict could be considered a good reason (not always, depends on whether the VP can run a meeting or what is planned to be discussed). As much as it would be nice to reschedule to a time when everybody can get there, sometimes it is not possible.

I agree with ScottMom#1 and LUVMYKIDS - pick the one most important and explain to the other about the conflict. Unless you truly believe they intentionally didn't check with you because they didn't want you there (which is a bit paranoid) I'd give them the benefit of the doubt.

BTW: You can complain about how the change was publicized. Our charter says we have to announce the dates of certain meetings at least 7 days before the meeting - it implies that if a scheduled meeting is changed we should give similar notice. (At our January meeting we voted to move the February meeting off of Valentines Day.)

I 2nd Scottmom. Choose the one you feel you need to attend most and send regrets to the other.
Even though you were supposed to speak at the one meeting, you could offer to send them a written report that they could share if you choose not to attend that meeting due to your prior committment.

OR....you mentioned there are a couple of you that are in this "pickle", what would be the harm in requesting to video both meetings and have a collective meeting or get together to view the meetings. I don't know....

This is when a clone would help SO MUCH!!!!

Though I have never been in this situation, I have been in the place where I was responsible for an event that was moved to a different date and people were upset that I couldn't follow through, even though I told them ahead of time what my schedule was. I think when you have more than one thing that is important to you, as most of us do, you will find yourself in these positions. It is only a matter of time.
My advice to you, pick the event you want to go to and send your regrets to the other. Just because you are supposed to speak at the first one does not make you responsible for going when they change their schedule without checking with those involved. Please don't beat yourself up or feel guilty (or let anyone make you feel guilty) about whatever decision you make. You are only human and can only be in one place at a time.