Timeline ruler divisions

While cutting and editing some video clip, originaly 36 minutes,
final clip is 24 minutes. Playing this clip I noticed I made some mistakes, cleared everything as new, imported the repaired clip into the program to make some corrections. Noticed that on the timeline ruler are still the old times from the original clip IE. 36 minutes, not 24.
Is it normal or wrong ?
Answers will be appreciated

How did you do that? If you use the Del key or Lift on toolbar/menu/shortcut to remove all things in the Timeline, then it will still show the old times because Lift does not remove time. In any case, the times on the Timeline are not reliable for the duration. see the time value after the slash after the Time spinner below the player.