What time would you set exterior lights to turn on and off?

December 26, 2018 6:46 AM

If you had to set an on and off time, for outside lights on a residential street with no public lighting (i.e. no streetlights, only porch and coach lights on houses), one time, for year-round exterior lighting, what times would you set, and what would inform your decision?

Assume this is a suburb on Long Island, New York, with no trees. Assume the street has 8 houses on each side. I'm looking for something like "Lights turn on at 5:00 p.m. EST and off at 8:30 a.m. because ...". Maybe there is some law or HOA rule that answers this, or maybe you want to time it related to sunrise/set, or maybe you want to minimize your electric bill, but provide some lighting for safety/security, etc. Any ideas and reasons welcome! What times would you set and why?

posted by Pig Tail Orchestra to Home & Garden (22 answers total)

Best answer: If it could truly not be adjusted, I would pick the earliest time it gets dusky in the winter (guessing around 5 in Long Islamd?) and the latest time the sun comes up (guessing around 9?) *estimates may be off because I live way up north.

The extra light won’t be noticeable/bothersome in the summer and it will be welcome in the winter. Good exterior lighting is really important for home security. To minimize unnecessary power use, make sure the bulbs are LED/CFL. Alternatively, although it doesn’t quite fit the parameters of your question, you can buy light bulbs with integrated light sensors that will turn on and off automatically.
posted by charmcityblues at 7:11 AM on December 26, 2018 [8 favorites]

Best answer: I would program the timer to go on at sunset and off at sunrise. Lights that are on at somewhat inappropriate times can indicate the residents are not home or not attentive to their lights.

I invested in this programmable solar timer switch five years ago, and I have not had to touch it since. It changes the on/off times based on your location and the changes to sunrise/sunset time throughout the year. My house has decorative outdoor wall sconces on this timer. If I had stronger spotlight type of lights, I suppose I would probably put them on a motion sensor.
posted by MyTwoCentsToo at 7:15 AM on December 26, 2018 [4 favorites]

If it must be a timer I would at the very least install one that you can set switching moments on as 'half an hour before sunset' or 'fifteen minutes after sunrise', a.k.a. astronomical timing. Even better would be one that also has a ambient light sensor, or even just an ambient sensor switch.
posted by Stoneshop at 7:21 AM on December 26, 2018

Best answer: I would do maybe 5PM to midnight if it had to be a fixed time period, or ideally ~ sunset to normal bedtime. Outdoor lights, to me, say either "we are home and expecting someone/willing to accept someone coming to the house" or "we are out and we want the lights on when we get home."

(Lights on a motion sensor are also good for security and don't give the impression that you're waiting for someone.)
posted by mskyle at 7:30 AM on December 26, 2018 [3 favorites]

There's been discussion around exterior residential security lighting in the push to control light pollution. There are supposedly studies that show all night exterior lighting often only serves as working illumination for thieves. While writing this, mskyle popped up with what I was going to suggest. Of the people I've known who live in semi-rural settings, having/not having a bright outdoor light on all night seems to fall along "cultural" lines.
posted by bonobothegreat at 7:34 AM on December 26, 2018 [4 favorites]

Best answer: If you have a legal obligation to provide lighting, find out what your local definition of civil twilight is, then use a sunset calculator for you location to determine that for the shortest day of the year.

The cost of putting in a sunset/sunrise responsive timer may be worth it in terms of energy savings. Nothing says "We're not at home!" louder than a light coming on at the same time every day.
posted by scruss at 7:37 AM on December 26, 2018

Best answer: I would go 4:30pm to 3:00am. It gets dark right now around 4:30, or dark enough where a light helps, and I would turn it off at the latest time one of my kids would be coming home and need the light to see the door. While I support home security steps, I personally would not be concerned about lighting my property after 3:00am.
posted by AugustWest at 7:47 AM on December 26, 2018 [1 favorite]

Please use lights that are not overbright and that don't contribute to light pollution.
posted by theora55 at 8:08 AM on December 26, 2018 [5 favorites]

Does the timer adjust for DST ?
posted by tilde at 8:17 AM on December 26, 2018

Response by poster: Does the timer adjust for DST ?

No. It has a 24 hour of day and day of week timer, but no reference to day of year.
posted by Pig Tail Orchestra at 8:25 AM on December 26, 2018

Best answer: I live in the country. I have two outdoor lights, both on light-activated timers (not this but similar), so that they come on automatically when it starts getting dark and then turn off a set number of hours afterward. That is what I would recommend, because it means the lights are on when I'm getting home and it's dark, but they don't contribute to light pollution or keep me up all night. (My neighbors have a utility light they sometimes leave on all night and it drives me crazy.)

If I had to set a timer to cover more or less when they're on now, in the time of very short days, it'd be 4pm to midnight.
posted by lazuli at 9:03 AM on December 26, 2018 [1 favorite]

Best answer: Here's sunrise and sunset times for Fire Island, wherever you are in Long Island may differ by a couple of minutes. If I honestly had to pick one non-DST adjusted time it'd be 6pm to 6am, since that'd cover darkness more or less.
posted by Nelson at 9:04 AM on December 26, 2018

It seriously depends on what your goals are. In my area it is not normal to leave exterior lights on all night (some people do, but they are a definite minority). I'd be looking to minimize light pollution and energy consumption, so I wouldn't have my lights on a timer at all; I would simply turn them on and off as needed, i.e. they'd be on if I was expecting company or was doing something outside that required them, but that's it. If I wanted them for security, I'd install motion sensors. Leaving exterior lights on all night is not something it would ever occur to me to do, and feels rather wasteful.
posted by Anticipation Of A New Lover's Arrival, The at 9:21 AM on December 26, 2018 [3 favorites]

Plus yeah, there's nothing like going out to the backyard for a little stargazing or fireside relaxation and having the neighbor's outdoor floodlight that they never turn off shining in your eyes the whole time. A friend of mine has a permanent grudge against his neighbor over a light like that.
posted by Anticipation Of A New Lover's Arrival, The at 9:36 AM on December 26, 2018 [5 favorites]

Response by poster: My goal is to expand my thinking regarding this question. Until I read some answers, it literally never dawned on me that one wouldn't keep one's lights on all night.
posted by Pig Tail Orchestra at 9:36 AM on December 26, 2018 [4 favorites]

If you aren't constrained by an already installed timer a photocell handles varying sunset times automatically (and even dark caused by heavy cloud cover). They can be paired with a timer to turn the lights off at either a preset time or after a specific number of hours of illumination. You can also use a motion detector to manage autodimming. This allows your lights to be on at 100% when people are moving around and then kick down to 30% or 10% when there has been no motion for a while. All three is the new hotness in parking lot and private drive lighting.
posted by Mitheral at 1:04 PM on December 26, 2018 [1 favorite]

Best answer: I think it depends a lot on what you think the purpose is. If you want it to light your driveway when you get home about this time of year, it's going to have to go on between 5:30 and 6:00 pm. (I'm across Long Island Sound in CT.) If you want it for security, it needs to stay on pretty late. I've read that cat burglars operate in the wee small hours when most people are in a deep sleep and not as easily disturbed. If it's just on general principles, I would find the sunrise/sunset times for the equinoxes, and make the turn on 20 minutes later and the turn off 20 minutes sooner. (Keep DST in mind.) A lamp on a timer inside the house helps keep it from looking unoccupied.

You don't say why you want to let it go year round without adjustment. It would make sense to change it with the leap forward/fall back times of daylight savings.

I was in the hardware store light section today and noticed they have bulbs (!) with motion detection. If you could find one that worked in your entrance door light, that would ease the problem of unlocking the door when coming in late. Or you could install one of the hi-tech door bell gadgets that do similar.
posted by SemiSalt at 2:19 PM on December 26, 2018

Best answer: If this has to be left running year-round, I would not do it at all, because it's a waste of fossil fuels and light pollution.

If it could be set only for winter, I would have it go on at 4:15, which is the earliest I come home from work and
it might be darkish, and off at 6:30, which is the latest any of us would come in. If we were going out again to come back later, I'd leave the light on manually.
posted by metasarah at 2:22 PM on December 26, 2018 [1 favorite]

Assuming that your outside lights are LED or CFL, and not too numerous, I wouldn't sweat leaving them on; it's pretty much a rounding error in terms of your household's energy consumption. A "60W" CFL or LED bulb typically draws 8-12W... compare that to the hundreds and thousands of watts many appliances use and it's not too much. I think people get a little overly fixated on lighting energy consumption because it's visible and readily controllable. Leaving lights on overnight seems like a good tradeoff to me to reduce the risk of crime, passerby tripping, etc. Dusk to dawn photocells are probably the smartest way to do it; we have a timer switch which you enter your dawn time, dusk time and location in, and it works just OK, but tends to kind of drift out of synch and need an occasional re-entry of dusk and dawn times as the season change. If I could conveniently install a photocell, I would.
posted by Larry David Syndrome at 5:37 PM on December 26, 2018

Response by poster: Crime. I can understand the argument that "lights help criminals", but is this true? I'd love to see links to studies, pro or con, regarding leaving lights on overnight. This is exactly the kind of thing I was hoping to learn from this AskMe.

It's 3 LEDs on one switch. This site says that it will cost me $3.91 per year of continuous use, so halve that for just overnight. Even incandescents would only cost $13 per year for overnight usage. Not killing the planet with this application. I was thinking I couldn't use a photocell because the porch light is in a recessed ceiling can, but is it possible to use one of the coach lights to trigger a photocell, for all 3 lights? But I also want to be able to turn on the lights manually?

>>It would make sense to change it with the leap forward/fall back times of daylight savings.

I'm planning on not changing anything, including the time of day. I'm not understanding why I would need to make this adjustment. I also understand that clocks drift, I'm not talking about that adjustment.

Light pollution. How about you come over and tell my 15 neighbors to turn off their lights, and then we can talk LOL
posted by Pig Tail Orchestra at 7:33 PM on December 26, 2018

Pig Tail Orchestra: " I was thinking I couldn't use a photocell because the porch light is in a recessed ceiling can, but is it possible to use one of the coach lights to trigger a photocell, for all 3 lights? But I also want to be able to turn on the lights manually?"

Both would be possible however it would require some fairly advanced electrical modifications for a homeowner DIY. You'd install a stand alone photocell controlling the circuit with an override switch.

MyTwoCentsToo: "I invested in this programmable solar timer switch five years ago, and I have not had to touch it since."

This is a decent solution but it does require a neutral (not a "natural") in the switch box which may not be there if you have an older electrical installation.
posted by Mitheral at 6:34 AM on December 27, 2018

Response by poster: I didn't realize their was a programmable switch that including the sunrise/set times. Thanks to those that mentioned that, because I just ordered one.
posted by Pig Tail Orchestra at 9:37 AM on December 31, 2018