Based on PM PrepCast and Formula Study Guide, here are the fomulas:
EF = ES + Dur - 1
ES = EF of prev (largest) + 1
LF = LS of succ (smallest) - 1
LS = LF - Dur + 1
Float = LS - ES = LF - EF
However, it was mentioned that there are other calculation methods, which where the Start Day is Zero.
I have searched and found this:
www.projectlearning.net/pdf/X2_1.pdf
As we can see from the PDF, the formulas are similar, but they start at Day Zero, and there is no +1 nor -1.
What is expected on PMP Exam ? Does it make any difference ?
Tarek.