A Riddle for a Clue!

A riddle is a riddle.
A quest is a quest.
But something isn't something
and wondering is for you.

A day after the 1/2ab of March
comes a rising of an impunity
for a is no less than 30 but no more then 32
and a b is a b and a b is a 2.

For the impunity is shaken or faken
and most definitely taken by you.