Since when did it become popular to shorthand years from
2020 A.D. to
2020? I haven't seen anything after a google search, and in fact I wonder if it was even popular to use A.D., ever. I don't recall a time I ever used it.
Here’s a quick survey of selected chronicles and histories of England from the 14th to 19th centuries, with quotes illustrating how the writers refer to years.
- Ranulph Higden, in Polychronicon (c. 1344), gives years in the form “Gratiae MCXXXVII Stephani primo” (1137th of grace, first of [the reign of king] Stephen).
- John Brompton, in Chronicon (c. 1436), gives years in the form “anno Gratiæ M.C.liij” (in the 1153rd year of grace).
- Thomas Rudburn, in Historia Maior Wintoniensis (c. 1454), gives years in various forms, for example “Anno ab Incarnatione Domini MXCIX” (in the 1099th year from the incarnation of the lord), “anno Dominæ Incarnationis MCXXXV” (“in the 1135th year of the incarnation of the lord”), or “anno Domini MCXCVIII” but when pressed for space he could abbreviate, for example, “Ab anno MCXLIV ad annum MCCXIV” (from the 1144th year to the 1214th year).
- Robert Fabyan, in The New Chronicles of England and France (1516), uses “Anno Domini M.CCC.lxxxxvii. Anno xx” (in the 1397th year of the lord; in the 20th year [of the reign of king Richard II]).
- Raphael Holinshed, in Chronicles of England, Scotland, and Ireland (1577), gives years in various forms, including “in the yeare of our Lord 1555” but also “the yeare 1550” or plain “1550”.
- John Norden, in Speculum Britanniae (1593), gives years in the form “the yeere of Christ 1549” or “the yere 1381”.
- Richard Baker, in A Chronicle of the Kings of England (1643), writes “the year 1553” or plain “1553”.
- John Milton, in The History of Britain (1670), writes “the year A.D. 915” or “the year seven hundred and forty-one”.
- James Tyrell, in The General History of England (1700), writes “the year 1118”.
- David Hume, in The History of England (1762), writes “the year 1679” or plain “1666”.
- Thomas Macaulay, in The History of England (1848), writes “the year 1451” or plain “1455”.
You’ll see that the only writer I found who uses “A.D.” in running text is John Milton. This is a very small sample, but if it’s representative, then I think the most likely answer to your question is that there was never a period in which many writers in English used “A.D.”!
The survey suggests instead that the following trends or developments took place.
Writers fluent in Latin described years however they pleased, for example in the survey above we have Brompton’s “anno Gratiae” and Rudburn’s “Anno ab Incarnatione Domini”. But in other authors you might find “anno saluto Christianæ …” (in the …th year of Christian salvation) or “anno Christi nati supra …” (in the …th year after the birth of Christ) or other phrases with equivalent meaning. This variety declined along with the use of Latin, leaving only the conventional “Anno Domini”.
The year number was originally understood as an ordinal numeral. This is clearest in Higden where “Gratiae MCXXXVII” is parallel to “Stephani primo” (first of Stephen), not to “Stephani uno” (one of Stephen). However, when these Latin phrases were translated into English, the number became a cardinal numeral. For example Holinshed writes “in the year of our Lord 1555” and not “in the 1555th year of our Lord”. This change allowed the number to become a kind of name for the year.
Writers in English increasingly shortened or omitted calendrical prefixes over the 16th and 17th centuries, so that by the mid-17th century it was conventional to write years as plain numbers, leaving writers like Milton who used “A.D.” in a small minority.