wikipedia:Gregorian calendar

Day of the week for a date in different years
Common years always begin and end on the same day of the week, since 365 is one more than a multiple of 7 (52 [number of weeks in a year] × 7 [number of days in a week] = 364). For example, 2007 began on a Monday and ended on a Monday. Leap years end on the next day of the week from which they begin. For example, 2008 began on a Tuesday and ended on a Wednesday.
Not counting leap years, any calendar date will move to the next day of the week the following year. For example, if a birthday fell on a Wednesday in 2006, it fell on a Thursday in 2007. Leap years make things a little more complicated, and move any given date occurring after March two days in the week on the following year, "leaping over" an extra day, hence the term leap year. For example, 2008 was a leap year, so calendar days of 1 March or later in the year, moved two days of the week from 2007.
Calendar days occurring before 1 March do not make the extra day of the week jump until the year following a leap year. So, if a birthday is 15 June, then it must have fallen on a Friday in 2007 and a Sunday in 2008. If, however, a birthday is 15 February, then it must have fallen on a Thursday in 2007, a Friday in 2008 and a Sunday in 2009.

「日暦算」というのがあります。
それと「閏年」が中途ではいって、「△年後の□月○日の
曜日を出しなさい。」
とか。
上記のところは、この計算を多少はスピードアップ
させてくれるような項目が掲載されていると。
個人的には思う。
月日の数え方というものに、いくつもの方法があったのだと。
時代と場所により、違ったと。
そうすると、どの数え方を採用するのか?
地球が実際に太陽を1周するのにかかる時間と、
暦が1年と「規定する時間」にずれが生じる場合に、
そのずれをどうやって補正するのか?
統一的に採用するとして、どうやってバラバラだった
数え方をまとめ上げていくのか。ユリウス暦を採用するのか、はたまたグレゴリー暦を採用するのかで同じ日時を
指す月日がずれる場合、一方に統一するときに
どんな問題が生じてきたのか?
どの暦が、どの国で採用されるのかということに関して、
キリスト教会の人たちはどのように関係してきたのか?
様々な地域の歴史や政治的事情がどのように絡んできたのか?
ひたすらそういうことが書かれている記事になります。
カレンダーや暦を無視して生活できる人はそうそう
いないわけですから。
生活に密接に関わるものの歴史の一コマを
振り返ってみましょうという。
そんなエントリー。

George Parker, 2nd Earl of Macclesfield, FRS (c. 1695 or 1697 – 17 March 1764) was an English peer and astronomer.
Styled Viscount Parker from 1721 to 1732, he was Member of Parliament (MP) for Wallingford from 1722 to 1727, but his interests were not in politics. In 1722 he became a fellow of the Royal Society, and he spent most of his time in astronomical observations at his Oxfordshire seat, Shirburn Castle, which had been bought by his father in 1716; here he built an observatory and a chemical laboratory.
He was very prominent in effecting the changeover to the Gregorian calendar, which came into effect in 1752. His action in this matter, however, was somewhat unpopular, as the opinion was fairly general that he had robbed the people of eleven days. When his son ran for parliament as a Whig in 1754, resentment over his role in the calendar reform was one of many issues raised by the son's Tory opponents; a famous 1755 Hogarth painting influenced by the events of these elections is the main historical source for the "Give us our eleven days" slogan.

wikipedia:Horace Walpole
フランス革命が勃発したとき、イギリスの政治家だったようです。
フランス革命が引き起こした政治的な顛末に対してはかなり否定的。
ギロチンに駆けられたマリーアントワネットに同情的な記述が見られる。
この人が残した書簡などは、歴史家の重要な資料になっている模様。
日本の感覚でいったら「世襲議員
そんなに、駆り立てられて勉強するわけでもなさそうな。でもスマートみたいな。

Indeed, Madam, I write unwillingly; there is not a word left in my Dictionary that can express what I feel. Savages, barbarians, &c., were terms for poor ignorant Indians and Blacks and Hyaenas, or, with some superlative epithets, for Spaniards in Peru and Mexico, for Inquisitors, or for Enthusiasts of every breed in religious wars. It remained for the enlightened eighteenth century to baffle language and invent horrors that can be found in no vocabulary. What tongue could be prepared to paint a Nation that should avow Atheism, profess Assassination, and practice Massacres on Massacres for four years together: and who, as if they had destroyed God as well as their King, and established Incredulity by law, give no symptoms of repentance! These Monsters talk of settling a Constitution—it may be a brief one, and couched in one Law, "Thou shalt reverse every Precept of Morality and Justice, and do all the Wrong thou canst to all Mankind"

wikipedia:Philip Stanhope, 4th Earl of Chesterfield