Got a scheduler showing 1 day, when I navigate to Sat it falls over when showbusinesshours = false.
Although Saturday has business set, looking at the screen in dp 5.6 seams to suggest that it contains no business hours.
So the issues are
.BusinessBeginsHour & .BusinessEndsHour are set but it appears to show Saturday as having no business hours
If there are genuinely no businesshours it should revert to showing all hours (or least give a error that states the reason)