Click the Global Tracks button
The arrangement marker appears at the start of the project, or at the end of the last existing arrangement marker.
In Logic Pro, drag the right edge of the arrangement marker left or right.
In Logic Pro, do one of the following:
Click the name of the selected arrangement marker, then choose a name from the shortcut menu.
Double-click the marker (except on the name), then enter a new name.
Download the guides:
Logic Pro User Guide: PDF