Make the outline a solid circle behind the clock part instead of just an outline. The reason for this is that the edges between the outline and the clock look worse if the outline isn't a solid circle in the background. Notice how the left side has rougher edges:

In general, it's a good idea to not make 2 shapes meet exactly at the edges due to issues with how SVGs are displayed. This isn't an Inkscape only issue either. It doesn't always need to be done that way, but it's especially necessary with shapes that have round edges. With straight edges, there will sometimes appear to be a thin gap between shapes even though there shouldn't be.

I think it might be a good idea to make it look more like a clock, but I'm not going to object to keeping the current look.