dose any one know when the clocks change to BST (British Summer Time) dose the off peak charging time also change with the time change or continue at GMT time?...some background to the question, my smart meter (installed by Ovo) only uses GMT time all year…… my home automation (Habitat System). runs in GMT so all appliances running on time switches via Home automation are on GMT using Habitat home automation I have managed to shift between 88% and 98% to off peak (using the Loop app data taken from my Ovo meter) of my electric usage to over night!
Answer
Is my smart meter on BST or GMT?
+3Best answer by Firedog
Updated on 26/06/25 by Abby_OVO
This is speculation on my part, but based on personal experience.
The peak/off-peak hours are set by the Distribution Network Operator (DNO), who know best how to balance their load. The timings are GMT all year round.
Some smart meters compensate for this when the clocks change, while others don’t. Some time switches powering off-peak equipment (e.g. storage heaters and immersion water heaters) also compensate, but it may take a manual adjustment to the timer clock to show the same time as other clocks in the house. It usually makes no real difference either way, unless you find that a heater is switching on at midnight when the cheap rate doesn’t start until 1AM (if this does happen, then the ON period should perhaps be adjusted to exclude the first and last hours of the advertised period).
It does however create a headache for those responsible for the usage and billing pages of the online account. This is my usage table for 30 October 2022:
| Before midday | After midday | ||
| Time period | Usage | Time period | Usage |
| 12:00am | - | 12:00pm | 0.08 kWh |
| 12:30am | - | 12:30pm | 0.09 kWh |
| 1:00am | 0.07 kWh | 1:00pm | 0.18 kWh |
| 1:30am | 0.03 kWh | 1:30pm | 0.09 kWh |
| 1:00am | 0.03 kWh | 2:00pm | 0.09 kWh |
| 1:30am | 0.03 kWh | 2:30pm | 0.09 kWh |
| 2:00am | 0.03 kWh | 3:00pm | 0.09 kWh |
| 2:30am | 0.04 kWh | 3:30pm | 0.09 kWh |
| 3:00am | 0.02 kWh | 4:00pm | 0.09 kWh |
| 3:30am | 0.04 kWh | 4:30pm | 0.10 kWh |
| 4:00am | 0.03 kWh | 5:00pm | 0.10 kWh |
| 4:30am | 0.03 kWh | 5:30pm | 0.11 kWh |
| 5:00am | 0.03 kWh | 6:00pm | 0.11 kWh |
| 5:30am | 0.03 kWh | 6:30pm | 0.11 kWh |
| 6:00am | 0.17 kWh | 7:00pm | 0.11 kWh |
| 6:30am | 2.92 kWh | 7:30pm | 0.11 kWh |
| 7:00am | 0.12 kWh | 8:00pm | 0.10 kWh |
| 7:30am | 0.09 kWh | 8:30pm | 0.09 kWh |
| 8:00am | 0.10 kWh | 9:00pm | 0.10 kWh |
| 8:30am | 0.09 kWh | 9:30pm | 0.10 kWh |
| 9:00am | 0.09 kWh | 10:00pm | 0.10 kWh |
| 9:30am | 0.09 kWh | 10:30pm | 0.11 kWh |
| 10:00am | 0.07 kWh | ||
| 10:30am | 0.09 kWh | ||
| 11:00am | 0.07 kWh | ||
| 11:30am | 0.09 kWh | ||
The extra and missing hours make it look strange, but even so, there are only 23 hours’ worth of readings. Stranger still, there are only 23 hours recorded for 31 March the following year. As far as I can tell, billing comes out right in the end. I’m not charged for an hour’s worth of heating at the higher rate when I shouldn’t be.
So, it certainly looks as if the timings for me are GMT all year round. You’d better check first what the hours are for your region:
“… use this table below; the first two digits of your MPAN is the ‘Area ID’; the ‘Off peak’ times are on the column second from the right:
Then check physically whether the meter is recording peak- or off-peak-usage during the first or last hour of night-time according to the clock in your kitchen. Make allowances accordingly!
If you’ve found this article helpful, then we actually have a related idea created by another community member which you may find interesting and actually agree with. Check it out below and if you agree, feel free to Upvote the idea!
+3sorry I know that I am asking about the off peak charging time on the Bill
+1- Plan Zero Hero
If you have smart meters, then probably not. Most don’t change for BST/GMT. Older meters might though
+3If you have smart meters, then probably not. Most don’t change for BST/GMT. Older meters might though
thanks so the time ( Billing) period on the bill for Off peak start / finish time is still at GMT irrespective of the clock change.
+3thanks …..Yes on the smart meter and according to the model spec I have it only has 1 time period that's GMT
- Plan Zero Hero
- Answer
Updated on 26/06/25 by Abby_OVO
This is speculation on my part, but based on personal experience.
The peak/off-peak hours are set by the Distribution Network Operator (DNO), who know best how to balance their load. The timings are GMT all year round.
Some smart meters compensate for this when the clocks change, while others don’t. Some time switches powering off-peak equipment (e.g. storage heaters and immersion water heaters) also compensate, but it may take a manual adjustment to the timer clock to show the same time as other clocks in the house. It usually makes no real difference either way, unless you find that a heater is switching on at midnight when the cheap rate doesn’t start until 1AM (if this does happen, then the ON period should perhaps be adjusted to exclude the first and last hours of the advertised period).
It does however create a headache for those responsible for the usage and billing pages of the online account. This is my usage table for 30 October 2022:
| Before midday | After midday | ||
| Time period | Usage | Time period | Usage |
| 12:00am | - | 12:00pm | 0.08 kWh |
| 12:30am | - | 12:30pm | 0.09 kWh |
| 1:00am | 0.07 kWh | 1:00pm | 0.18 kWh |
| 1:30am | 0.03 kWh | 1:30pm | 0.09 kWh |
| 1:00am | 0.03 kWh | 2:00pm | 0.09 kWh |
| 1:30am | 0.03 kWh | 2:30pm | 0.09 kWh |
| 2:00am | 0.03 kWh | 3:00pm | 0.09 kWh |
| 2:30am | 0.04 kWh | 3:30pm | 0.09 kWh |
| 3:00am | 0.02 kWh | 4:00pm | 0.09 kWh |
| 3:30am | 0.04 kWh | 4:30pm | 0.10 kWh |
| 4:00am | 0.03 kWh | 5:00pm | 0.10 kWh |
| 4:30am | 0.03 kWh | 5:30pm | 0.11 kWh |
| 5:00am | 0.03 kWh | 6:00pm | 0.11 kWh |
| 5:30am | 0.03 kWh | 6:30pm | 0.11 kWh |
| 6:00am | 0.17 kWh | 7:00pm | 0.11 kWh |
| 6:30am | 2.92 kWh | 7:30pm | 0.11 kWh |
| 7:00am | 0.12 kWh | 8:00pm | 0.10 kWh |
| 7:30am | 0.09 kWh | 8:30pm | 0.09 kWh |
| 8:00am | 0.10 kWh | 9:00pm | 0.10 kWh |
| 8:30am | 0.09 kWh | 9:30pm | 0.10 kWh |
| 9:00am | 0.09 kWh | 10:00pm | 0.10 kWh |
| 9:30am | 0.09 kWh | 10:30pm | 0.11 kWh |
| 10:00am | 0.07 kWh | ||
| 10:30am | 0.09 kWh | ||
| 11:00am | 0.07 kWh | ||
| 11:30am | 0.09 kWh | ||
The extra and missing hours make it look strange, but even so, there are only 23 hours’ worth of readings. Stranger still, there are only 23 hours recorded for 31 March the following year. As far as I can tell, billing comes out right in the end. I’m not charged for an hour’s worth of heating at the higher rate when I shouldn’t be.
So, it certainly looks as if the timings for me are GMT all year round. You’d better check first what the hours are for your region:
“… use this table below; the first two digits of your MPAN is the ‘Area ID’; the ‘Off peak’ times are on the column second from the right:
Then check physically whether the meter is recording peak- or off-peak-usage during the first or last hour of night-time according to the clock in your kitchen. Make allowances accordingly!
If you’ve found this article helpful, then we actually have a related idea created by another community member which you may find interesting and actually agree with. Check it out below and if you agree, feel free to Upvote the idea!
A couple of weeks ago someone commented it’s hard to determine his Power Move as what he calculates doesn’t match what OVO says.
When I look at my usage the figure on the first screen doesn’t always match the second screen.
The difference here isn’t much, just 0.08 kWh, but sometimes it’s as much as 0.25 kWh. That doesn’t sound much, but it’s nearly 10% of my daily use. I know rounding will make a difference, but surely not that much? Most days it’s the same or 0.01/0.02 out. I wonder which is the correct useage?
Also, on occasion it doesn’t update correctly and shows I’ve used power between midnight and 1 in the morning but nothing else all day. This only started after the clocks went forward in spring. Could it be a timing issue?
None of this really bothers/affects me, I’m just curious. This could answer the chap’s comment, but search as I have, I can’t find the original post.
I have noticed the same thing. I don’t think OVO usage is based British Summer Time, still on GMT or Universal Time or whatever it’s called nowadays.
I meant to add to my last message is that the curious thing about the clocks issue is that it gets free hours and Power Flex events in the correct time periods.
It is a concern of mine. I put the washing machine on timed and then went out as normal. It did the washing during the time slot but flex said I did not move anything. Ok I used 0.16 kWh as it was a cold wash on a hot day but still more than the 0.05 kwh min the say about. I believe that the times link with the time the meter updates the ovo servers and mine are about 6 min late looking at the reading. Therefore its difficult to get an accurate reading
- Plan Zero Hero
When I look at my usage the figure on the first screen doesn’t always match the second screen.
I think you’ll find that this difference reflects the different figures used to calculate a day’s usage. The Day page shows half-hourly (Hh) data, the sum of which gives the daily total. Other usage pages - Week, Month, Year - work out the daily total by subtracting yesterday’s meter reading from today’s. Hh figures for a day are now shown using BST, but meter readings are always snapshots of the status at midnight UTC. So discrepancies in the daily total arise if there are significant differences between usage in the interval 00:00-01:00.
Noel | I have no official status; I'm just a volunteer who comes here to help other customers. My gear: Aclara SGM 1416-B Electricity-only E7 meter; Chameleon IHD3-PPMID-AAA | It may look as if I know what I’m talking about, but don’t let that fool you. |
Hey
Just a reminder that Power Move & the Power Move Flex trial are 2 different products. If you want to discuss the Power Move Flex trial we have a trialists group here.
Was asked to comment on this topic by your system so I did. If its not in the correct area the request shouldn't go out and you comment should be there. Poor......
Log in to the OVO Forum
No account yet? Create an account
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.