letting native date construct date

instead of moment falling back to native date
bypasses deprecated warning
fix #915
I'm not entirely sure just sending the string through `new Date` here is a good idea.  Newing up Date objects can throw exceptions if the string if not formatted correctly, which is handled down lower on line 371.  This should probably either be safer, or this entire chunk of code re-written to consolidate some of the error handling code pieces.