My gf flew to Islamabad yesterday. ba.com says that the flight (BA129) arrived at 0601, when in fact it arrived at 0701. Not because it was an hour late, but because Pakistan are currently 5 hours ahead, not 4 (they've
extended daylight savings time for a few months to save electricity). Not just last night's flight either -- searching for LHR-ISB for the next week (at least) says it's an ~8 hour flight that lands ~12 hours after take-off... which is +4.
I've contacted customer services by email, mainly because I (and my gf) would like to know what's going to happen to her return flight. Specifically we're interested in which of the departure and arrival times are correct, since they can't both be!
I flew back from ISB about six weeks ago and the flight took off at 9:10 on a Sunday. I did get an email from BA about this, though, but I believe it was because I had bought the ticket
before the hour-forward time change was announced and thus the take-off time had changed.
The rule of thumb I have always used is that the take-off and arrival times from LHR are always correct. You can figure out the rest from there. It seems that ba.com aren't recognising the time change properly.