A Windows programme for calculating the distance between two dates (inclusive and exclusive) between 1 January 1155 and the present day.
Source and Programme Released (CC-BY 4.0) M. H. Beals
Please push all suggested improvments and clone/branch all variations (so that I can see what interesting additions you come up with)
v.1.0.3 Updated to correct miscalculation of short year (1751)