McHappy is a prefix used by McDonalds in Australia. It's their way of supporting charities and sell alot of Big Macs at the same time.

McDonalds crew doesn't usually like McHappy Time or McHappy Day as they are forced into selling 'Helping Hands' and Big Macs rather than do their usual job. On average McDonalds can raise about $10,000 (au) per store for local charities and their Ronald McDonald house for children with special needs.

Generally McHappy Time is the last 2 weeks of June and on the 1st of July is McHappy Day.