At this time the WWP does not attempt to determine or record whether specific dates are in the Gregorian or Julian calendar. At some time in the future, we will research the feasibility of encoding this information. In encoding Julian dates, we would use the same basic format as for other dates (ccyy-mm-dd), and specify “Julian” as the value of calendar=. The WWP extensions to the TEI DTDs restrict the values of calendar= to a closed list of “Gregorian”, “Julian”, and “undetermined”. The default value is “Gregorian”.
Although we do not attempt to determine from external sources whether a given date is in the old style or not, there are some cases such as diary entries, historical narratives, or other systematic ordered date records where the dates are clearly old-style (e.g. the sequence of dates runs December 1643, January 1643, February 1643, March 1644). In these obvious cases we will encode a modernized value (e.g. January 1644, 1644-01) on the value= attribute of <date>. In the absence of such information we will assume the date is new-style.