The current day is always placed on the right side. You can use the diagram to find out when a backup took place or which client computer was active and prevented the server from sleeping. 

The diagram uses 11 colors. When you have more than 11 items, the colors are repeated. The diagrams are created from left to right in the same order as the legend from top down. 

Sources, which are only displayed and not used for monitoring are displayed with a dashed style.

Operation of Lights-Out