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How the clock change can accidentally add to your energy bill

Alicia Hempsted
Written by  Alicia Hempsted
Kara Gammell
Reviewed by  Kara Gammell
5 min read
Updated: 01 Apr 2025

Check that your smart meter isn't stuck in the past when the clocks are changed, or else you might accidentally add to your energy bill.

On Sunday 30th March, the clocks sprang forward to British Summer Time (BST). While the clocks on most of your devices should adjust automatically to the change, some devices won't. This can include timers on your energy meter,

If you’re on a time-of-use tariff, also known as Economy 7, need to be aware that the clock on the meter may not automatically change to BST, but the off-peak times set by the provider will change with the clocks.

This mean that you might be charged the higher single rate tariff for your energy use during what you might think is off-peak hours.

What is Economy 7?

Economy 7 is an energy plan that offers two different energy prices depending on when you use it. It's also referred to as a multi-rate plan or a differential plan.

During times of day when people are most likely to use energy – peak times – a higher rate is applied. Using energy during off-peak hours, on the other hand, gets you cheaper energy, For some providers the cost of off-peak energy use can be as much as 50% cheaper compared to peak hours.

How can I tell when off-peak hours start?

Economy 7 plans will usually come with a smart meter that shows you two different readings – one for standard energy use. You won't be shown any obvious indicators that off-peak hours have started on your smart meter, so it's important that you keep track of your energy bill.

Kara Gammell
Kara Gammell
Personal Finance Expert

Make sure you're getting the most out of off-peak

Peak and off-peak hours are usually split between day and night, with cheaper rates offered between around 12pm and 7am. However, times can vary slightly depending on your provider.

You should check the terms of your contract or visit your energy supplier’s website to double check your off-peak times, to be sure you’re getting the best value from your tariff.

To find out if your off-peak times have changed with the clocks, you may need to run a test or speak to your provider.

If your smart meter hasn't recognised that the clocks have sprung forward to British Summer Time (BST), you’ll need to adjust any timers you have set on the appliances around your home, such as your hot water tank or washing machine.

Off-peak times are defined by your supplier, so unfortunately you can't just adjust them to suit your needs. If you think there is something wrong with the timings on your meter and you're being charged more than you should be, you should contact your provider to report the problem.

They may be able to fix the problem remotely or send out a technician to help.