Is it a private ceremony or a group ceremony? An in-person ceremony or a virtual ceremony?
My group citizenship ceremony a few years ago had taken about an hour and a half to two hours.
If it is a group ceremony, there will likely be a few talks by the mayor and/or other civic dignitaries about the meaning and significance of citizenship, the oath taking, the anthem and then some pleasantries after that. It won't be quick.
You may want to defer the work meeting or request permission to be late on the safe side.
I am not a lawyer or immigration advisor. My statements/comments do not constitute legal advice. E&OE. Please do not PM me for advice.