I do not believe that there is a way to do that in QuickBase but I have recently recently been working with clients who are heavily involved with timelines and Gantt charts and this is definitely a feature that they expect on Gantt charts. That is a feature available on the add-on from MCF and also competitive tools like "Wrike".
I suggest that you put in a user voice on this. Can do that by going to the my apps page and looking for the little orange tab on the left of the screen.
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Mark Shnier (YQC)
Quick Base Solution Provider
Your Quick Base Coach
http://QuickBaseCoach.com[email protected]------------------------------