If B16 (which is a date) is between January 1st. and June 30th. then 3
If B16 (which is a date) is between July 1st. and September 30th then
2 If B16 (which is a date) is between October 1st. and December 31st.
then 0 If B16 5 years then 4

Maybe this gets what you want:

=IF(B16DATE(YEAR(TODAY())+5,MONTH(TODAY()),DAY(TO DAY())),4,
2*(MONTH(B16)<10)+(MONTH(B16)<7))