AIO time. GMT or BST? Specifically or Intelligent Octopus GO

Apologies if this has been asked before.
Can anyone provide some advice as I can't get my head around the settings.
Givenergy use GMT?
Octopus use BST (GMT+1)?
To take advantage of the 23.30 - 05.30 Octopus cheap rate slot, the Givenergy charge time needs to be set for 22.30 - 04.30?
Thanks in advance.

set the times to 23:30 and 05:30 in GivEnergy

mikes01666 Givenergy use GMT?

No, the inverter gets set to local time by GE each time the clock changes. You should see it in the activity log.