Hi @wmykura , the times are defined by the supplier and must be set by them. If they are wrong, the system can be set remotely - you need to contact customer support. 

Note: don’t forget that the peak/off peak times differ by region
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If you post a screenshot of your Plan page, we can see what hours apply for you. As BP says, they vary by region, so we’d need to know that too. 

This is my Economy 7 plan page; I’m in the East Midlands, region 11, also called _B:
  

You may be able to spot your region on this map:
 

I am in Southern Scotland - region 18.

Here is my plan.  It doesn’t actually state the hours but they are: 11pm-7:30am Night Rate.

I’m not actually with OVO for this account but with Octopus.  I’m changing to Octopus Go Intelligent tariff - it gives 11:30pm-5:30am at 7.5p kWh, and a cheaper day rate.

So it’s a choice between 8.5hrs at 16p, or 6hrs at 7.5p - for Night Rate.  I recon 6 hours is enough to charge my storage heaters, so am going for this.

But I need to adjust my smart meter to switch on the storage heaters between 11:30pm-5:30am (on the 5th meter tail), to avoid importing at peak rate.  Octopus might change this automatically when I change tariff - but I doubt it.  So I need to find out how to change this or get it changed.

I’m not sure IO Go is for storage heaters but for EV’s, Heat Pumps etc. The supplier will change any settings needed - it’s not something you or an electrician can do unless there is a separate time switch. Octopus will charge you depending on the time of use (ToU) so you will need 30 min readings set up.

Just looking at the FAQ’s for IO Go 

I am on 30 minute readings.  I can go onto my account and see my 30min reading history  every day.  This is what Octopus use for billing on smart tariffs.

Octopus GO is for EVs and I have one of these - but it also switches the whole home onto the cheap rate between 11:30pm-5:30am - which is great.  But for the storage heaters (5th meter tail) I need the on/off times to match the cheap rate.

Otherwise I’ll need to put manual timers on the heaters, which is not desirable.

Ok so you need to get Octopus to change it. You can’t do it yourself

The fifth contactor is activated by the Auxiliary Load Control Switch (ALCS) according to a calendar set by the supplier and sent to the meter by an ‘Electricity Configure Auxiliary Load’ (ECAUL) command. The calendar should (and will normally) match the tariff timings, which are agreed between the supplier and the DNO.

Re: Intelligent Octopus Go

Yes, Getting onto Intelligent Octopus Go is not straightforward.  You need a working smart meter, and a compatible EV or EV charger (there are only 5 compatible chargers).

Octopus then take control of the charging.  Then, you need to do a ‘test charge’ when Octopus begin charging the car, and check whether the extra load is recognised by the smart meter.

If this works - you’re in!  Then you get cheap electricity at 7.5p for a guaranteed 6 hours, PLUS you get extra hours at 7.5p when the electricity is cheap, and this is for the whole home.  The cheap period is calculated as soon as you plug the car in.  I frequently find that the cheap rate will start at 10:30pm and run right through to 9am.

But it varies day-by-day - at weekends the cheap rate will often start at 8pm, and often have a couple of hours cheap rate in the afternoon.

I’ll have to defer to BP from here on in, because he’s our resident Octopus expert. 

I think OVO go about this by using an app to record what passes through the EV charger, then applying a discount to the energy bill. This means that the domestic meter isn’t involved at all, and there’s no way a customer can syphon off cheap juice to power his storage heaters or his tumble dryer like the Octopus system seems to allow for. 

That said, if your meter were set up for Economy 7, with the ALCS switching and the offpeak register recording between 23:30 and 06:30, you’d be taking full advantage of the tariff’s cheap rate for your heating. You’d have to find out whether Octopus will be able to set this up.

This is mainly about the switch circuit. 
Octopus do allow whole house usage during ‘off peak’ via Intelligent Go but if part of the connection isn’t switched in, it won’t be live. 
Bottom line though is the supplier would need to configure the 5th terminal or change the meter for one without one

A quick byline @wmykura , a few friends tell me that it’s more straightforward to apply via the app, not on the web portal - depending on your EV setup