Britain did not convert to the Gregorian calendar until 1751, when 11 days had to be added to their dates to get the Gregorian dates. In 1639 they were 10 days behind the Gregorian calendar.
Re: Klein Tools Or Greenlee. Both Klein and Greenlee are TOP quality tools with a niche market. They have a few common tools (such as rabis and ratchet cutters) and either is worth buying over pretty much anything else. They are not really direct competitors. I prefer Knipex for most hand tools except linemans.
1 Chapman Tools (Durham, CT): midget ratchets and adaptors for Allen, Bristol, Phillips, and TORX fasteners since 1936 to repair and service everything from firearms to appliances, computers to dental equipment.  Craftsman brand hand tools, made for SEARS by Danaher Tool Group, are now a mix of USA-made and imported.