Quest Web Parts for SharePoint does not yet contain a Gantt Chart. There are several requests for that so we may do that in the future.
I assume that you use our Quest Calendar View webpart here. The only view that does not show the hours of the day in our Calendar View is the Month view. If you don't mind using the Month view, you can set it so that it starts in Month view and additionally, disable the other view in the Calendar Appearance tab in the web part configurator. I hope that works for you.