I can't understand why it will take time.
Just thinking out loud here but should the new timetable schedules not be effective immediately? It's not like a new pair of shoes in that you have to 'run them in'.
Is it that the drivers have to 'learn' new routes?
Maybe it was 'cause it was a frosty morning. Or there was a leaf on the track. Or a driver slept it out. Or maybe the wind was slowing up progress. We'll never know anyway, 'cause they don't even apologise for being late any more. Not that it means much, but it's just common courtesy.
It appears that all this padding in the timetables ain't hiding the skeletons in the closet...