The format of the show is activities, songs and games with either host passing back to each other at the end of their segment, and frequently joining each other in activities. Each day the presenters look at the calendar to find out which day of the week it is, read a story, and look through the windows. From 1976 to 2000, they had a clock shaped like a rocket, and from 1966 to 2000, a clock shaped like a flower. Until 2000, the windows looked almost exactly like their British counterparts with a few slight differences. They changed the background behind the windows from black to white at the end of 1967 and they then changed it to light blue in 1985. In 1987 "Play School" had a mild makeover for its 21st anniversary on air; there was a mild cosmetic revamp to the set, with a new set of opening and closing titles with a new version of the theme song sung by presenters, Philip Quast and Jennifer Ludlam. The windows also changed to look like to ones used on the British version of the show, but this change was not well received and the windows reverted to their old style by 1988, which remained until the major 2000 revamp.