As another first day of the month passes, people are quick to shout out 'White Rabbits' or 'Pinch. punch, first of the month' and I'm guessing that they have no idea why they do it except that everyone just does.
So my curiosity gene kicked in and I can inform you that not surprisingly, saying 'White Rabbits' is supposed to bring you luck. The superstition is a purely British one and there is a variant in which you say 'rabbit, rabbit, rabbit' three times to achieve the desired effect. Ideally the word 'rabbit' should be spoken up the chimney apparently. What a curious nation we are to be sure.
As for 'pinch, punch, first of the month' this is another British oddity. The phrase was used to banish witches with a pinch of salt (which weakened the witch) followed by a punch to send her on her way.
Over time this altered to playfully pinching and punching a friend or relative but it is important to add '...and no returns' or else they may do it back to you!