Question Day Trip to a Glacier from Bergen or Oslo?

I posted a couple of days ago about a day trip to a glacier while on the Norway in a Nutshell trip. I'm still trying to decide if it's better to start from Bergen or Oslo. Has anyone done this? Which city offers a more scenic or convenient route to a glacier? I'm also curious about the logistics, like how early you need to start and if it's feasible to do in a day without feeling rushed. Any recommendations on specific glaciers to visit would be great too!