As much as I do like and appreciate Bootstrap, I don't use it for all (or even most) of my work. I wish these directives, or at least the ones where this could make sense, weren't so dependent on it.
You can use totally custom templates for every directive and it should basically work out of the box for most of them (with some proper CSS style of course).
Thanks, I'll check that out then. Looking for something for calendar fields specifically.