I like the Gormanian and Holocene calendars; but I use the Gregorian for compatibility with the rest of humanity.
Also, as I live in Britain, I use an unholy mixture of metric, imperial, and archaic measurements.
Length of an object? Centimetres. Height of a human? Feet and inches. Mass of flour? Grams. Mass of a human? Stones, pounds, and ounces. Distance by car? Miles. Distance on foot? Kilometres. Volume of a soft drink? Litres or millilitres. Volume of beer or milk? Pints. Volume of non-dairy milk? Also litres and millilitres.
The letter arrived yesterday.