Slight thread drift but where do you get official landing times, i.e. that would have legal status? I’ve recently tried to get a LGW arrival time for a few weeks ago, not necessarily accurate to the minute, the airline won’t help and I suspect Flightstats etc. would not be considered official.
Leaving aside the fact that "landing time" and "arrival time" don't necessarily mean the same thing, the airline certainly isn't the only place to look.
The airport will have captured that information (so that they can display "Landed 10:33" on the flight information screens) and Air Traffic Control will also have logged the runway movement and time.
Other possible sources are Mode S, ADS-B and ACARS.
Out of interest, what was the flight number and date?