Complex Formula Involving Dates & Times -

The formula to give 1 for first and last appointment and 0 otherwise (Assuming this formula is in column O):

Formula:

=IF(OR(COUNTIFS(B:B,"<"&B2,B:B,">"&INT(B2))=0,COUNTIFS(B:B,">"&B2,B:B,"<"&INT(B2)+1)=0),1,0)

The formula to give 0 for first and last appointment and 1 otherwise:

Formula:

=1-O2

You can add an additional filter to see if the appointment has been canceled.