there's no such commands, sorry... besides changing the numbers (hours:minutes:seconds) of the time display itself.
options are you may work with the edit-head and edit-tail movable blue-markers or set fixed markers on the timeline (see View > Tempo Map / Markers... or double-click on the time-ruler header);
then, Transport > Backward [|<] and Forward [>|] will stop at the previous and next markers, or the start and end-of-timeline resp. whichever comes last in either direction.
there's no such commands, sorry... besides changing the numbers (hours:minutes:seconds) of the time display itself.
options are you may work with the edit-head and edit-tail movable blue-markers or set fixed markers on the timeline (see View > Tempo Map / Markers... or double-click on the time-ruler header);
then, Transport > Backward [|<] and Forward [>|] will stop at the previous and next markers, or the start and end-of-timeline resp. whichever comes last in either direction.
hth.
cheers