Intermatic ST01 7-Day Programmable Digital Timer Switch - Heavy Duty In-Wall Light & Appliance Control with Astronomic Self-Adjusting Technology (White) | Perfect for Home Automation, Energy Savings & Vacation Lighting Control

Installation was straightforward. I thought programming was simple enough but our porch light would turn on automatically but did not power off in the morning.I emailed Intermatic late at night, received a reply within hours that provided a direct phone number.The Customer Service Representative got me set up in a matter of minutes and the switch now functions perfectly.I highly recommend the timer AND Intermatic customer service.All I wanted was a programmable light switch. I was tired of manually setting the on/off timer every few weeks using the 1960’s Intermatic clock (see the photo - amazing that it still works). But what I got in this product is a full-on astronomical computer with a very thoughtful set of options, way more options than I need. First, the astronomical computer. The software in this device accurately calculates sunset and sunrise, year ‘round, for several latitudes in North America. (Which reminds me: Flat-Earthers need not buy this product.) There are books written on how to calculate rising and setting times using software. This product implements those algorithms. But wait, there’s more: the device automatically sets the day of the week and daylight savings, so that you don’t have to. Impressive.Downside: the initial setup is comically easy, but entirely unintuitive. Other reviewers have complained. I say: appreciate the ingenuity. All this space-age technology, setup with just 4 multi-purpose buttons and a tiny LCD screen. As others have recommended, sit at a table with the instructions for the initial setup, or just a dress rehearsal. You’ll learn it after just one or two times through. But you’ll quickly forget the steps because you won’t need to touch the device for a year or two when the internal battery needs changing. Anyhow, it all takes maybe 5 or ten minutes. I guess one way to have improved it would be to add a smart phone app that does the setting over Bluetooth, but then you’d have a different set of problems. I haven’t reviewed all the other options, such as the random on/off to fool your neighbors; the different settings for days of the week; etc. but they are all there. This is obviously a well engineered product that has evolved to a high level of sophistication over time, sold at a consumer-level price. I’m so impressed.PS: there’s something deeply satisfying about upgrading the post-war mechanical Intermatic device, 50 years later, with a high tech Intermatic device. America! Heck yeah.This is more of a troubleshooting tip than a review.If you have one of these switches and it KEEPS CLICKING ON AND OFF repeatedly, keep reading.I installed one of these and it worked great for 14 years! Then one day I noticed that the switch was turning the lights on and off repeatedly. The switch wouldn’t stay turned on OR off. It would just sit there and click ON and OFF every second. I tried resetting it and installed a new battery. It didn’t change anything. I figured the switch had gone bad, so I replaced it. The new switch did the same thing! I couldn’t find anyone online who had the same problem.If this is happening AND you have this device installed in a 3-WAY switch setup, you may have it wired incorrectly. This is what happened to me. The timer switch worked perfectly *IF* the second switch in the circuit remained in the same position. However, when the second switch was flipped in the wrong position and the timer turned the lights on, the switch would immediately start the never-ending clicking ON and OFF. All I had to do to fix this problem was to flip the second light switch in the circuit back to the other position. Note: My switch is probably wired incorrectly for a 3-way situation...so I need to check that to fix it permanently. But for now, this has solved my problem.There’s nothing in the trouble-shooting instructions about this. I had completely forgotten that this unit was installed in a 3-way switch circuit! The second switch in my case is in a place where you would never use it. Someone must have bumped the second switch at some point into the wrong position…and that’s when my problem started.works great, even after a power failure.Instructions were difficult to follow for setting schedule. Unlike its predecessor, turn off time is on a different setting from turn on, (eg it is now “schedule 1 -turn on, schedule 2 -turn off). It used to be schedule 1 on and off all one setting. I called the hot line and a very knowledgeable lady talked me through it in 5 minutes. They need to be more explicit in the last part of the instruction sheet. The unit itself is excellent. I appreciate it being able to turn on at sunset and off at 11PM saving electricity with the varying day length. PFSWorks as advertised. Very functional. Same model as first 2 units I installed 16-ish years ago. "Clocks" always run fast, 10-15 minutes every 6 months on the 2 older timers units. Easy to reset in 1st step of "set-up". Went back for another anyways. This unit is only 2 weeks in. Body is so large, I had to "trim" 3 box fastener tails in the standard 3 gang in-wall box, and other adjustments. Hour and a half install on this one. Did not have these issues on first 2 units. Plus, lacks display back lighting. Could be a 4-5 star item if not for these.Update: 20 months in, still working. Replace cheap supplied battery upon installation, use Duracel, Energizer, etc. Too bad manufacturer did not provide optional power tap for optional display backlighting. Oh well... Are you listening Intermatic? Power tap?Update August 2022: Got 4 now. All going strong still. First 2 older timers had "fast clocks". The 2 newer timers one is bout 2 minutes slow per year, other is bout 3 minutes fast per year. Not bad.Great little timer. It is important to note, however, that the actual clock/controller part of the timer is powered by a CR2 3V lithium non-rechargeable internal battery (all the time). If the battery is dead, the timer will not work and you will not even be able to switch the load manually. The timer comes with the battery. My brand new timers battery lasted 2 weeks before going dead (must have been a "dud"). Anyway, I replaced the battery and it is now working fine again.My mom bought this item dozens of years ago, and it finally bit the dust. So I went on to Amazon if that model was still available, and sure enough, it was! Ordered it, installed it, and it works like the original. It was perfect.A must for old houses with no Neutral wiring available. It lacks the fancy backlight LCD in the dark but who cares, you set it once and forget it (unless you need to replace the battery once a year, theoretically). Installation is a two minute affair, make sure you set that breaker off before you mingle in there! A+ product!