When changing the settings, the timer (days) starts over at the day the change is made. Plumbing tape is needed - the thin white "tape" where the faucet and the timer attach.Works well. Use it for dual impulse sprinklers on new sod.Essential when I’m out of town on these 95+ temp days.Good investment in a quality control water unit. Have multiple unit which have been proven to be reliable. I would recommend it to anyone willing to invest in a quality and dependable unit.I would suggest removing it from the faucet during the winter months. Also, it doesn't like direct sunlight and gets hot and shuts off. I put a towel over it during the hottest days and that worked.The timers are really easy to use and work as advertised, I used them for the past summer with only a couple of issues. I had to remove the intake screen filter as it plugged of with particle from my well water. Well, water is not filtered first so there are hardness and some tiny particles that eventually plugged the filter. I removed the intake screen filter with a normal hose washer and the problem was solved.The other problem I haven't been able to figure out is there was a slight drop in water pressure going through the timer, this occurs with the newly install timer but hasn't got worse over time. I have 20 of these timers (duels and singles) and they all have this pressure drop. Not a big issue just don't get the same water spread from my sprinklers as I do without the timer. Sprinkler without timer 80 foot spread. With timer 70 spread.Reliable and easy to program. You don't need to be tech savvy to figure this thing out. Running 2 months now on the same batteries. Purchased it for my mother in addition to an irrigation hose. Set one side to operate on a regular schedule and the other side for manual operation.Build quality feels solid despite the use of plastic. It's heavy, which inspires confidence. But not so heavy that you'll worry about it stressing a pipe. To reduce strain on the faucet, I purchased a kink protector and now do not worry about someone pulling on a hose and stressing the fixture. http://www.amazon.com/gp/product/B000XTH2FEIf you plan on using an irrigation hose, be sure that you have a vacuum breaker in place. Many cities now require them on new construction outdoor faucets, but older homes generally do not have them. A vacuum breaker prevents backflow (from an irrigation hose or otherwise) re-entering your home's drinking supply (and the city's water supply). This is important with irrigation hoses because they are laid bare or buried underground, where fertilizers and other chemicals can seep into them. A brass vacuum breaker costs about $8 and will last a long time. http://www.amazon.com/gp/product/B0046HA9S6Purchased April 5th 2021.Installed and used from April 2021 to October 2021, then disconnected and stored in attached garage.Re-installed again, March 2022, used for 2 weeks, on 14 March 2022, went to use it and it leaks every where.It's leaking from somewhere inside and also where the hose attaches, there is a split.Very easy to program, nice clear display, build quality leaves something to be desired as it only lasted 7 months.I've only had this unit for 1 week and it has, so far, worked great for me. The setup was easy and the interface was straightforward. I used the rain delay once and it worked fine for me, starting back up after the selected duration. I haven't experienced any leaks as some reviewers noted, but I did use plumbers tape on all the connections.The only reason I'm giving this 4 stars is because you cannot select multiple start times. In others words you set one start time (ex. 9am) and you can only program the unit to activate based on preset intervals relative to the start time you selected (you are limited to 12hr, 24hr, 1 day, 2 day, etc intervals). In other words, I cannot have my unit start at 6am and 8pm daily. In the above example, it would start at 9am then 9pm, if I had selected the 12hr interval. All in all a good product.Great duel zone timer. Does exactly as advertised