Hi everyone. I have a question regarding the change in timetable I observed on the BRU-LHR route before and after the daylight saving time change end of march. In my case, I am supposed to take the first BA flight of the day from BRU to LHR (BA389) to catch a LHR to LAX (BA283). At the time I travel, end of april, BA389 departs at 07.30 and arrives at 07.45. BA283 departing at 9.35 this gives a 1.50h connection.
Here is the thing I don't really get : if I do the same route, but before the change of clocks, let's say march 24, also on a tuesday, BA389 departs at 06.40 and arrives at 06.55, almost one hour before, and BA283 departs at 10.25 leading to 3.30h connecting time.
I understand that the change of time is a complex thing and that it affects the time table. But I don't see why the first plane of the day from BRU is postponed for so long.
So I checked for other european airports, on the same days (march 24, before the change, and march 31, after), for the first flight of the day with BA :
AMS-LHR : dep. 07.45 arr. 08.05 on march 24 ; dep. 07.15 arr. 07.30 on march 31 (connecting time goes from 2.20h to 2.05).
CDG-LHR : 07.50 - 08.10 changed to 07.30 - 07.45 (connecting 2.15 to 1.50).
FRA-LHR : 07.25 - 08.15 changed to 07.30 - 08.15 (connecting 2.10 to 1.20).
GVA-LHR : 07.30 - 08.15 changed to 07.35 - 08.15 (connecting 2.10 to 1.20).

Can anyone clarifies the logic in such a difference between BRU and other airports. Could it be because the aircraft flying that route would come first from another aiport ?
It is not permanent, because in November, after another change, the BRU-LHR flight departs again at 06.40.

I am very curious of the reason.
Thanx