Augustus did not steal a day (or more) from February to August (named Sextilis until 8 BCE) so that August was as long as July.
from http://janusquirinus.org/
Ling Ouyang asked:
LO> That reminds me: Do we trust Macrobius' account of Julius Caesar' calendarfrom http://janusquirinus.org/
LO> reform? Because if we do, then Sextilis had already 31 days (Sat. from http://janusquirinus.org/
LO> 1.14.8)--Augustus didn't steal days from February/September. And Februaryfrom http://janusquirinus.org/
LO> was kept short because of festivals, no? (1.14.7)from http://janusquirinus.org/
Yes. There is an indirect indication in Varro, De Re Rustica 1.28, written in 37 BC. This gives the start dates for the seasons and their lengths. The two items are only consistent if Varro's months had the modern lengths.
from http://janusquirinus.org/
Direct evidence comes from pOxy 61.4175, an ephemeris table from year 6/7 of Augustus in Egypt (=24 BC) giving both Egyptian and Roman dates, first published in 1999. This explicitly equates Kal. Sex. with 8 Mesore and Kal. Sept. with 4 Thoth -- 31 days later. This same papyrus shows that the Roman civil calendar was synchronous with the Julian calendar in 24 BC. See A. M. Jones, ZPE 119 (2000) 159-166, also C. J. Bennett, ZPE 142 (2003) 221-240.
from http://janusquirinus.org/
As far as I can trace it, the story that Augustus stole a day from February to lengthen August comes from the Compotus of Johannes de Sacrobosco, written in 1232. Its not in Bede, and Sacrobosco doesn't indicate a source for it -- if anyone knows of an earlier source I'd like to know of it. My current guess is that Sacrobosco thought that the Caesarian calendar "ought" to have been more regular in its alternation of 31 and 30 day months, since this was, in his opinion, a more rational structure, and that he came up with this theory as an explanation for why it wasn't.
from http://janusquirinus.org/
Chris
