Martin Steer wrote: > >> And the mention of January 1662-3 above should be a hint that dates are >> another can of worms better dealt with by an OO approach > > Given that dates are just data, I don't get this. You'll have to tell me > why this is so. 1. The above date is prior to the adoption of Gregorian dates in England & her colonies. The year, especially in church usage, was often taken as starting on March 25th. Sometimes the first three months are simply given as being in the same year as the preceding December (1662 in the above case), sometimes with a dual year as above and sometimes as new-style dates (1663 in my example). Conventional RDBMS only deals with the new-style (hopefully it will also know about September 1752 - run cal if you don't know about that one). 2. Dates aren't necessarily precise. Using the Civil Registration indexes for the UK, for instance, one will simply get a month and this is the month at the end of which quarterly returns were sent in to the central office so that March 1845 means Q1 1845 and Q1 could, in fact, include events from late December 1844. 3. Early legal documents might be dated by regnal year. e.g. Elizabeth I succeeded in November 1558 so an event in December 1559 and one in September 1560 would both be in 2 Elizabeth. 4. Documents might be undated. For instance one document which I think names one of my earliest ancestors by surname is undated but the archivists list it as "early 14th century". There's evidence which suggests to me that it should collate before a document with a 1295 date. Given the fact that the archivists' date is only an approximation this isn't really a contradiction but a dating system should recognise that. -- Ian The Hotmail address is my spam-bin. Real mail address is iang at austonley org uk