MS Excel If statement not working for shifts formula?

AE has formula :

=IF(
              AND([@[IST Time]]>=$AF$1,[@[IST Time]]<$AG$1),"First (6a-3:30p)",
              IF(AND([@[IST Time]]>=$AG$1,[@[IST Time]]<$AH$1),"Second (1:30p-11p)",
              "Third (10p-7:30a)"))

it should have shown Second instead of third , not sure what's wrong here.