Calendar is causing budget to change

this is based on your resource and what you have set for Default Units/Time if it is set to 8/d

then it takes 8*the duration and give the manhours 

so fo the duration is 10 days the 8*10= 80 manhours or units 

you can change them manually or do them all at once then export to excel change the manhours save it then import back into P6

A bit more detailed explanation please, Cynthia.

You add an actvity with what duration on what calendar

Then you add a resouirce assignmnet record, with a resource on what calendar

you add 100mhr into whiich field

Which budegeted labour units field (resource or activity) then says 80, or is it both