One way:
They are those which were born in year 2016-18 during a month between 1 and 6.
EXTRACT.

Can you please read the link I gave you and try to do it by yourself.
I gave you the algorithm and the function to use you just have to try.

Note there are examples of the function in the link and these examples are exactly what you have to do to answer your problem.
If you can't do it, come back with your tries.

If you just want people who turn 18 between 01 January 2016 and 30 June 2016 then all you need is add_months to add 18 years to their date of birth and the BETWEEN operator.

cookiemonster wrote on Wed, 21 September 2016 04:20

If you just want people who turn 18 between 01 January 2016 and 30 June 2016 then all you need is add_months to add 18 years to their date of birth and the BETWEEN operator.

can you write a sample script fot that? thanks

blogbeka wrote on Wed, 21 September 2016 20:17

cookiemonster wrote on Wed, 21 September 2016 04:20

If you just want people who turn 18 between 01 January 2016 and 30 June 2016 then all you need is add_months to add 18 years to their date of birth and the BETWEEN operator.

can you write a sample script fot that? thanks

Yes, we can write the SQL, but this is your task NOT ours.

Show us what you have tried.

 FLOOR(MONTHS_BETWEEN('01/01/2016',date_birtday)/12) = 18