I talked with the tech folks at a irrigation timer manufacturer and it is possible to use a digital timer with the Hydro-Indexing valve. I assume the same applies for other digital timer manufactures. Here is how it is done, at least for the one manufacturer. The timer is wired to single electric valve as a single zone. The timer allows multiple programs to be run. So two programs are used, program A and program B. Within each program there can be up to 4 start times. Thus, program A is used with 3 start times and program B is similarly programed with 3 start times. (This assumes the indexing valve controls 6 zones). The advantage of digital are as follows: a) The length of watering time is more manageable. My existing timer is programmed (if that is a correct term) in multiples of 12 minutes. With the digital I can program it to any multiple of minutes. This translates into real $ for folks on city water. b) Less likelihood of getting city code watering violations. In my area, irrigation is only permitted on certain times and days of the week. The electro mechanical clock occasionally needs to be reset due to the frequent power outages we experience in this area. When the time drifts due to the power outages, irrigation occurs outside of the allotted time. During dry times the city gets aggressive, although I have never gotten a fine I have gotten warnings. c) Optimal timing for watering. When the electro mechancal timer drifts due to power outages, the irrigation events occur outside of the optimal late night / early morning hours. d) Safety. My particular electro mechanical timer provides 110V to the solenoid. With the digital, a safer 24V is used. Assuming that I can get the desired amount of water in 18 minutes per zone, then I should be able to reduce my water consumption by 25%. (The mechanical timer would require two 12 minute periods whereas the digital would require 18 minutes. Thus the savings is 25% = (24-18)/24. Actual savings will depend on the individual irrigation system itself and time of year. (e.g., perhaps your system provides adequate watering in 20 minutes which means your savings would be 12.5%.) I post this because I others asking this question on other sites.