The source for davening at chatzos (any day) is no less than a ???? in ?”?) ???? ????) . This special ?? ???? lasts for 2 hours. So although the entire Purim is a ?? ???? , this is the highest point of any day. And just because you said tehillim last year does not mean you have not yet been answered. It means only that you have not yet seen or been shown the answer! May you be ???? to see it ?????!
There is no such thing as a ????? in vain!