Need help with Awards and Honors on UC Application

I have 4 awards in computer science (1st, 2nd, 2nd, and 4th place in contests). For my last one should I put another computer science award (3rd place)? Or should I put in NHS for the sake of variety. In the event that I choose NHS, what would I put for the date? I asked my NHS advisor and he said that NHS is a year long activity and he wouldn’t know a set date to put in.