Adaptive frequency is a smart feature of RainMachine that allows skipping a programmed cycle if the quantity of irrigation applied is too low to be beneficial to plant growth. It promotes healthy plant growth by enforcing deep root penetration of the water applied. The decision to skip or not depends on available water in soil, plant root depth and soil type but it boils down to a minimum water quantity that should reach a percentage of plant roots. The quantity of water that wasn't applied due to a frequency skip will be added to the next watering cycle. For the customer, this translates into less frequent but longer duration irrigation.
For example, with this feature enabled, a daily program, depending on weather, might skip more than 1 day and water only 3 days in a week. The adaptive frequency applies to the base program frequency (daily, every 2 days, weekly etc), this means the skipped cycle will go to the next programmed cycle not in the next day, for example, an every 2 days programs that skip a cycle will start the next cycle after 2 days.
In the above screenshot from the RainMachine web interface, the Tue, Wed and Thu will be skipped and plant water needs will be carried over to Fri when it will water for 54% of the summer water necessities.