EV tariff - GMT and BST

Can we have a definitive answer to this question? Some answers say the off peak timing is always on GMT, whilst others say it depends on your meter, or even where you live. The only thread which seemed to be answering this question disappeared to a link which says:- Oops! That page doesn’t exist or is private.
I have just signed up for your EV tariff and need to know whether the off peak (2-6am) tariff is always timed to GMT or automatically changes to BST. i.e. do time clocks have to be kept at GMT or when BST is in operation, there is no need to alter clocks or the timed period to get the benefit of the off peak tariff.

I have since found this on the Bulb website:-

These are the off-peak and standard hours for the EV Tariff. They’ll stay the same, even when the clocks change:

Rate Hours
Standard 12am to 2am 6am to 12am
Off-peak 2am to 6am

But previously I had been told:-


Jun '20

Hi @bill6768

When I said that, I meant that the offpeak hours on a meter will vary meter to meter, so when they’re active depends on that particular metering setup. There is no universal answer unfortunately.

It depends on what is called the ‘standard settlement configuration’ (SSC) of the meter. Different SSCs will have different offpeak hours, and some are BST and some GMT. I agree this can make it overly complicated for people to understand when their offpeak hours are, which is why all 2-rate meters we install have the same SSC now.

I’ve had a look into your metering setup and can confirm your meter operates on GMT year round, apologies you’ve had such trouble getting that answer.

The last paragraph is at odds with the EV tariff details.

Does anyone know the answer for sure?

Hey @bill6768 Thanks for your post.

The smart meters update automatically between GMT and BST however I will need to get confirmation from the EV team if this is the same for your tariff, leave this with me, I will get an answer and let you know

–Carl :bulb:

Hi @Carl_at_Bulb - I wonder if you could check my meter too? I’ve noticed a nearly £1.50 difference between the “daily” price in the Bulb app Vs the “monthly” price for the same day and I wonder if it’s because my smart meter (pre-bulb) is billing in GMT instead of BST.

I would include screenshots showing the price discrepancy but apparently new users aren’t allowed to upload images? That’s not very helpful…

Would really like to know which price is correct and whether I need to change the programmed time on my car charger to GMT or not …

Well, well, well. I don’t seem to be the only one who is confused over this, twice yearly, predictable problem.
Bulb website says:-

“These are the off-peak and standard hours for the EV Tariff. They’ll stay the same, even when the clocks change:”

which is completely unclear.

Does it mean the off-peak hours are GMT and they stay the same (i.e. GMT) throughout the year, or does it mean the off-peak hours (2am to 6am) are 2-6 GMT and 2-6 BST (no need to adjust the programmed timings to GMT).

If Bulb had added GMT (or for that matter BST) to the off-peak hours, it might have been clearer.

For example:-

Rate Hours
Standard 12am to 2am 6am to 12am GMT
Off-peak 2am to 6am GMT

[GMT throughout the year regardless of BST]


Rate Hours
Standard 12am to 2am 6am to 12am GMT and BST
Off-peak 2am to 6am GMT and BST

[the meter takes care of the clock change and the rate applies 2am to 6am GMT and 2am to 6am BST]

I know, it’s complicated, but Bulb should know and be able to answer this simple question!

Sorry, but it seems clear enough. If the hours are eg 0200 to 0400, then they’ll always be that no matter whether it’s GMT or BST.

But that’s not the case with the economy 7 tariff, which I have been reliably informed by Bulb stays on GMT when BST kicks in. The question I am asking is, as it’s the same meter whether you’re on economy 7 or the EV tariff, does the EV tariff stay on GMT, like economy 7.

I have had contradictory answers from Bulb help. Via email I was told “It is set on GMT and unfortunately it doesn’t change to British Summer Time.
During this period your would have to adjust your usage by one hour.”

Then via Bulb on Twitter, ‘“the EV tariff always runs from 2am-6am. This tariff is only available with a functioning smart meter, so the meter updates automatically when the clocks change.”

I have turned off all storage heaters until I have a definitive answer and am running my washing machine at 3am until then. This information needs t be correct and clearly visible on the tariff details. Is it 2-6 in the winter and 3-7 in the summer or 2-6 all year? Not a trick question!