In these times of high fuel costs, you may also have experienced a reduced thrust take off, which also saves engine wear.
The following refers to jet aircraft and does not necessarily apply to piston engined or turboprop aircraft.
Reduced/Flex/Factored Thrust take offs are the norm and have been for many years (I first started doing them 30 years ago). The chances are that almost every take off you have experienced as a passenger in the last 20 years has been subject to some degree of thrust reduction.
As to your question:
Just how much longer was it, compared to the standard 20 degrees at/around MSL?
I am afraid that that is very difficult to answer. Time is not a parameter that is calculated or derived in the takeoff calculation. Neither is the distance from brakes off to rotate (Take Off Run Required - TORR); from which time could be calculated with knowledge of the rotate speed; calculated separately, as this is normally taken into account by the "Balanced Field" method of performance calculation where the Take Off Run and Take Off Distance Available is reduced to the lower of the two figures. I shall not go any further into take off performance calculation, as whilst it is not rocket science or even quantum mechanics, it can rapidly come to resemble pages of flute music!
If you had the page from the 747 performance manual for the appropriate runway at KUL, then by inspection and guesstimate you could probably come up with a figure of sorts. How accurate it would be I really could not say.
I hope that this helps to some extent.
YS