When Phil is in the garage and tries to get the sun glasses from the cupboard, he puts a chair on a box in order to reach them. The height of the chair differs from the moment he puts it on the box (in the background is a ball and the chair is above that ball) to the moment he climbs on the chair (now the chair barely covers the ball).
Everyone went to school and work on Valentines Day, but in 2010 Valentines Day was on a Sunday.