The manual for the 90-series thermostats states that when Monday is programmed first (pressing VIEW the first time jumps to the Monday program), all cycles are copied to the other days of the week. Alternatively, one can do this copying via the COPY key.
I found this worked the first time I tried it (all weekdays got the same program), but each subsequent time I programmed Monday it did not get copied to the other days of the week. I can get it to work with the COPY key, but the cycles defined for Monday aren't copied automatically.
Is the automatic copying only supposed to work the FIRST time Monday is programmed? Not very useful, if it is.