Let’s say the electricity got cut off and I go to sleep. When I wake up, if the electricity is back, I would like to know what time exactly it got restored.

Is there a mechanism I can set up to find out what time the electricity is restored after it was cut off?

5 Answers 5


I have a mains powered digital clock. It has no backup battery and the time is reset when the power comes back on. The display flashes until I set the time, but continues to advance from 00:00 so I know there has been a power cut (if I was out) and I can work out when the power came back on, because it is telling me how long ago it was.

I also have the type of time switch that rotates by electric motor, with pegs to flip its internal switch. At power loss it stops turning, and at restoration it continues without being reset. So this device tells me how long the power was off, from how slow its clock is.

From those two clocks I can also work out when the power loss occurred.

  • You may not even need a separate mains powered clock. The clock in my microwave also resets to 0:00 whenever it loses and regains power. Many appliances today have integrated clocks, maybe you'll find that you already have one in your home.
    – Elmy
    Commented Apr 21, 2022 at 13:49
  • My microwave does not have a clock, the gas cooker does. But I leave them both switched off anyway because there is another clock in the room. Commented Apr 21, 2022 at 15:33

With an analog clock, you can determine the amount of time that the power was interrupted. This will only tell you the total time over a single outage or covering multiple outages. It is necessary to set the clock to match another timepiece and then compare the two when you awake.

To determine the restoration time, one would have to have a clock which resets to 12:00 but then continues to count after it initializes. I have had such clocks, but it is not considered a marketable feature and does not usually appear in marketing literature. It also would not serve the desired purpose if multiple outages are involved. Finding one might be trial and error, or conversation with multiple digital clock owners.


Where I live, if I've called the power company to notify of the outage, their "power restored" message (voice to my voice mail, or text) will give the approximate time (nearest 15 minutes, seemingly) when power was restored.

  • 1
    Well that's location based, over here (Israel) we can only dream of such service. Side effect of having one company only which provides electricity. :-( Commented Apr 17, 2022 at 12:11
  • @ShadowWizardSaysNoMoreWar Our ability to change power companies is dependent on our ability to move house, so at any given address, there's really only one company providing power. There are places in the USA where that's not the case, but not many.
    – Zeiss Ikon
    Commented Apr 18, 2022 at 11:12
  • Still, imagine one single company for the whole of USA. The power they have, literally. Here they blackmail the government to get salaries that Hi Tech managers can only dream about, for example. Nobody can say "no" as it would mean blackout of the entire country. Commented Apr 18, 2022 at 11:40

The Ready, Set, Go Lifehack.

Is there a mechanism you can set up to find out what time exactly…
Short answer: Yes.

There's the thing: The power is out. You want to go to bed instead of waiting up in the dark to find out when it comes back on.
Here's how:

  1. Find an electric (analog) clock. (That's the mechanism part).
  2. Plug it in.
  3. Set the hands to the correct time (using your wrist watch/phone/battery powered clock, etc.).
  4. Go to sleep.
  5. When you wake, the clock will be 'off' by the amount of time since you set the hands and the electricity came on (and started the clock) and the correct time now.
  6. Done.

Good Luck

  • It's very hard to find electric analog clock. Quick search on Amazon brought hundreds of results, after checking random 10, all only battery operated, I gave up. Maybe such thing exists; But this hack requires extra effort of finding such a thing. It is not as simple as it appears to be. Commented Apr 20, 2022 at 11:11
  • 2
    @ShadowWizardSaysNoMoreWar and any comment Reader…What a clever question for Lifehacks. Where to find (or get) an analog electric clock. I wonder how long it will take for the question to find its way to StackExchange Lifehacks.
    – Stan
    Commented Apr 20, 2022 at 14:00
  • 1
    @ShadowWizardSaysNoMoreWar It's easy to make one out of any that use batteries. Hint: Battery eliminator.
    – Stan
    Commented Apr 21, 2022 at 14:39

I found a way to do it without any special clocks, although you need to do some investigation beforehand.

What you need is a Wi-Fi router and a smartphone with a good battery. I will use an Android phone in my explanation.

The Idea

As mentioned in How often does an Android system scan Wi-Fi?, Android phones regularly scan for Wi-Fi networks and try to connect to them, if you have Wi-Fi on but are not connected to any networks.

In the case of your home network, it should connect automatically once the network is detected. There are also apps that can help you confirm how often your phone tries to do this.

The idea is to leave your Wi-Fi router plugged in, and to leave your phone on and with Wi-Fi turned on. So, when the electricity is back, your phone will connect to the Wi-Fi. Then, there are ways to view logs or statistics to find out what time the power came, but you need to have experimented with it beforehand.

How to Check

You might be able to see at what time your phone connected to the Wi-Fi (see How can I see what specific times my phone has connected/disconnected to Wi-Fi?).

Alternatively, you might be able to connect to your router and find information about when the router went back up or what time your phone was connected to it.

Usually, you can connect to your router by typing its IP address in your browser. For example, in my case it is If you do not know the IP address of your router, you will usually be able to find the default IP address by searching for the model online. You will probably also need to log in, and you can also find default credentials for different models online.

Once you are connected, you might be able to find an event log which contains information on when the router went back up. Or you might be able to find a list of connected devices and for how long they have been connected.

  • Why would you leave the phone at home, just so that you can detect the time of a rare power cut? Commented Apr 22, 2022 at 19:38
  • @WeatherVane I don't get what you are asking. The question was about being at home and going to bed during a power outage, and wanting to know at what time during the night the power came back.
    – hb20007
    Commented Apr 23, 2022 at 8:12

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