Digital setback thermostats are mainly available in 5+2 day and 7-day configurations. The difference between them in terms of flexibility is that you can set a group setting with 4 different time settings for Monday-Friday in the 5+2 day configuration. In this configuration, you can also set Saturday and Sunday as a separate group with up to 4 different time settings per day. And, in the 7-day configuration, you can program each day differently with up to 4 different time settings per day.