Display Gantt chart on a week basis

Although time unit is day, is it possible to change the time display on the Gantt chart’s calendar into weeks or months? my project is over 4 years.

Did you try clicking “zoom out”?

In this context: It would be great, if GP would have numbered zoom levels:
1, 2, 3, etc.
or
25%, 50%, 75%, 100%, 125%, etc.

This way, one could zoom in and out and come back to a specific zoom level to get the best output for e.g. a rastered image.

Thanks, Tobias