Is there a term for days that are not present in all (Gregorian) calendar months? E.g. January has 30 and 31 but February doesn't. What are days like 30 and 31 called? update: The word, if it exists, ...
I have three years I am putting on a chart: current year, last year, and I'm not sure what to call the year that came before the last. Does it have a name? Would it be "pre-last"?
Obviously every year is annual. Every two years is biennial. Does the English language have a term for every 18 months?