One for the Wiki, is it midnight UK/GMT or midnight local time?
I was travelling today on the in-bound leg (GVA - LHR) in J, and went in at 00:01 local (GVA) time to change the flight online but the system showed no options.
I called up the Gold line, they told me that they can only change it at 00:01 UK/GMT time (which then is 1:01 GVA time), and that that is the policy.
I couldn't find anything on BA.com, curious if anyone else has had this experience or knows where to find the T&Cs here?