Neatline and BC dates

Playing around with neatline today and not sure where the best place to ask this sort of question is. I figured I would post it here and then ping someone at Scholars Lab about responding to it here.

I wanted to set a neatline item to 310 BC. I tried -310 and 310BC. Is there any format I can enter that get the item to show up on the BC side of the timeline?

I'll have to look into this further. This Jewish History timeline example on SIMILE's site has BC dates, so it should be technically possible, but I"m not sure yet what we might need to change in Neatline or NeatlineTime to make this possible.