Growing up in Yorkshire, it was common for family members to quickly announce ‘a pinch and a punch, the first of the month’ while demonstrating those very actions on me as a prank! One source has it: 'The victim may respond with "a flick and a kick for being so quick" and the original attacker may then reply with "a punch in the eye for being so sly"'. Another notes that the tradition should only be expressed before midday. Another popular saying is ‘white rabbits’, and if memory serves, you could avoid being pinched and punched if you said this first thing to your sibling. But I wonder why we say these in a lot of English-speaking countries, and are there similar traditions in other countries?
There are several theories, but one is that the first English proverb originates from mediæval times when people believed in witches. Salt was believed to make witches weak, so the pinch part of the saying is the pinching of salt - and the punch part was to banish the witch once she was weakened by the salt.
I’m informed by both native French and German speakers that nothing is said in France or German-speaking countries on these particular days, but if anyone reading this has information to the contrary, please add a comment!
Sources
https://en.wiktionary.org/wiki/pinch_and_a_punch_for_the_first_of_the_month
https://funkyenglish.com/pinch-punch-its-the-first-of-the-month/
https://www.itv.com/news/channel/2015-05-01/why-do-we-say-white-rabbits-on-first-of-the-month/