Have a good week

People leaving on a Friday afternoon always are wishing others to "have a good weekend." How come we don't have people wishing others to "have a good week" on Monday morning? We seem to be able to have fun and relax over the weekend without well wishers but the work week can be tough. Maybe a little boost would be nice. Of course being chipper on a Monday morning could get you a punch in the nose. Well let me be the first to encourage Monday morning salutations (don't forget to duck) .