Well, I do not keep the cable plugged in to my CM11a. Also, I still see the Dusk time as within 5 minutes.

What I mean is that if I tell a light to go on/off at a specific time it is always correct.

However, if I tell it to go on 15 minutes before Dusk, it can be 5 minutes too early. For example, it says dusk is at 7:05 PM, so 15 minutes before dusk should be 6:50PM, but it goes on at 6:44 PM. I have cleared the CM11A and removed the battery backup, and the software confirms the dusk time of 7:05 but it comes on at 6:44. My off time is 1:00 AM and it goes off at that time so the clock is good...and I do not have security set. This is a nit, but strange. I wonder just where the 6:44 comes from and it will do this for several days. OH DST seemed OK, except 1 light that was supposed to go off at 12:15 AM did not. I wonder if DST triggers at midnight instead of correcting at 2 AM?