Our Calendar

an rule of intercalation. If the number of any year be exactly divisible by four it is leap year; i

= 472, no

= 472, re

= 472, re

= 472, re

= 473, no

urth year being lea

that completes the century, a common year, if not exactly divisible by 400; so that only every fourth centurial year is

ears amounts to three days. This is corrected by the Gregorian, by making three c

U

is the tenth of 4,000; therefore, multiply the last product by 10, and we have the error in 4,000 years. Now, as the discrepancy between the Julian and Gregorian year is three da

UTI

a day. Now, (? × 4) = (1 × 3) = 3: the Julian rule gaining three days, the Gregorian suppressing three days in 400 years. (3 × 10) = 30, the number of days gained by the Julian rule in 4,000 years.