Foundations of Scottish Genealogy 8 of 12: Numbers, Dates, Calendars, Money and Measure in Scotland

So you spend three bawbees on a chopin of ale and two ells of lawn on Michaelmas Day 1640. How much was that, what did you get for it, what was it worth in Sterling equivalent and when exactly did this take place? What date, exactly, was IV Kalends Februarii MDCVIII in Scotland and in England? And why do the Scots celebrate Hogmanay (New Year) more than Christmas? The answers are not obvious!