I have a pair of Bose Companion 2 Series III’s. I wanted a simple 2.0 set that looked unassuming and sounded good. I bought them refurbished for about half the price and it’s a great set if you have the same requirements as I did. The sound is good for a home office/gaming set in a small room. Clear, bassy where needed and way louder than you’d probably need.
I believe there’s a whole section of one of the books devoted to the in world-calendars and their relation to the Gregorian one.