To take an opportunity to do something when the
time and conditions are near perfect or available.
From agriculture, when farmers gather the long
grass growth of summer to dry it to produce hay as winter feed for animals; The best
time to cut and dry the hay is during sunny days.
A:"There's a sale at K-mart this week - You wanna see if the have something for your sister's
birthday?"
B:" Sure - Might as well make
hay while the sun shines, and
get her something at cut price!"