The duration of one week is 10080 minutes.
60 * 24 * 7 = 10,080
In the Scheduler, you can use CellDuration="10080" in order to show one cell per week.
In DayPilot Pro 5.8 (build 1956) and earlier, there is a bug in the demo. The year view demo page uses an incorrect value (CellDuration="10800") which causes incorrect week starts and ends. This bug is fixed in build 19.69.