Note 76 — Chapter XXVII · THE CALENDAR AND ITS REVISION.
Reading edition
It should be observed that a distinction is made between the Julian and the historical year. This comes from the fact that when astronomical phenomena are calculated for dates B.C., it must be remembered that chronologists are in the habit of designating by 1, or rather by-1, the first year which precedes the instant of time at which the chronological year commenced, while astronomers mark this year in their tables by 0. It follows, therefore, that the rank of any year B.C. is always marked by an additional unit in the chronological dates. For the Christian era, of course, chronologists and astronomers work in the same way. The following table, given by Biot, exhibits the connection between these two methods. In the latter Biot shows the leap-years marked B, and the corresponding years in the Scaligerian chronological period are also given.
Dates of Julian Years commencing on January 1.
According to Chronologists. According to Astronomers. Corresponding years of the period of Scaliger.
-6 -5 4708
-5B -4B 4709
— — —
-4 -3 4710
-3 -2 4711
-2 -1 4712
-1B -0B 4713B
Physical instant when the era commenced.
+1 +1 4714
+2 +2 4715
+3 +3 4716
+4B +4B 4717B
— — —
+5 +5 4718