The online edition of the IPMs will in this respect be superior to the printed calendars.
The rendering of all dates into the Gregorian calendar, moreover, can tell us more about the inquisitions themselves and the efficiency of government.
Most years were denoted by the regnal year, while the day was given in relation to a particular liturgical feast.
For instance, the inquisition for Richard de Halsam in Yorkshire is dated to ‘Thursday after St John the Baptist 29 Edward I' (which was 29 June 1301). See iv.3.] Earlier calendars did not convert these dates into modern form, whereas volumes 19--1447 substitute modern dates. Cheney, A Handbook of Dates for Students of British History, revised edition by Michael Jones (Cambridge, 2000).
The various dates of writs, inquisitions, extents, deaths and proofs of ages contained within the IPMs up to 1399 therefore requires standardisation. Those requiring modern calendar equivalents need to look the date up in C. Cheney's A Handbook of Dates for Students of British History, (an impressive feat of scholarship but something that non-specialists are unlikely to have close to hand).[2. See also: Providing the modern equivalent of the dates will make the IPMs more user-friendly and accessible to a wider audience.
Currently, around 25,000 dates have been converted.
It is estimated that the final number will be around 40,000.
The dates will be inserted into the XML markup in ISO format (YYYY-MM-DD), while the original dates will be retained in the calendar text.
Part of this process involves enabling non-specialists, who may very well be unaware of medieval concepts and conventions, to interpret and understand the information contained with IPMs.
Standardisation of information contained with the IPMs into modern forms increases their accessibility. During the middle ages there was no fixed method of expressing the date.