Meeting today with KMF, JJ and SM about regnal dates. These are conclusions:

• We need to split Julian dates into three kinds: julianmarch (Stow's version of Julian, with the year beginning March 25), julianjan (Cheney's version, which Holinshed also seems to prefer, with the year beginning on Jan 1 (Cheney) or at "Christmas" (Holinshed -- I think we can use Jan 1 for this too), and juliannotsure, for dates where the beginning of the year is not clear.
• We need processing for Gregorian versions of all three (with the last being a combination of the two others).
• Stow Julian dates need to be switched to julianmarch.
• Other Julian dates need to be assigned to one of the three, depending on evidence.
• SM's excellent spreadsheet on regnal dates needs to be turned into a set of nested tables, with reigns containing tables of years, each year being a row with a unique id (william_1.3 for the third year of William I's reign), and each date for the beginning or end of a year being a date element tagged with the appropriate type of Julian value. This needs to be rendered into a handy reference page.
• Tagged regnal dates in Stow and elsewhere need to be linked to the appropriate row in the regnal date table using the -custom attributes.
• Rendering code needs to be written for the regnal custom attributes so that there's a useful mouseover popup, and clicking on them actually retrieves the relevant row of the regnal dates table as a popup with full info.