CHAPTER LIII. 53
Add 38 to the lower number and multiply the sum by
II. Divide the product by 703, and subtract the quo¬
tient from the upper number. The remainder in the
upper place is the number of the civil days, and the
remainder in the lower place is the number of the
avctmas. Add i to the number of days and divide the
sum by 7. The remainder shows the day of the week
on which the date in question falls."
This method would be correct if the months of the
seventytwo years with which the calculation begins
were lunar. However, they are solar months, in which
nearly twentyseven months must be intercalated,
so that these seventytwo years are more than 864
months.
We shall again exemplify this method in the case of Application
our gaugedate, i.e. the beginning of Eabi' I., A.ii. 422. method to
Between the abovementioned ist of Sha'ban and the date^^"^^
latter date there have elapsed 2695 months. Adding
these to the number of months adopted by the author
of the method (864), you get the sum of 3559 months.
Write down this number in two places. Multiply
the one by 7, and divide the product by 228. The
quotient represents the ctdhimdsa months, viz. 109. Rage 229.
Add them to the number in the other place, and you
get the sum 3668. Multiply it by 30, and you get the
product 110,040. Write down this number in two
different places. Add to the lower number 38, and
you get 110,078. Multiply it by 11 and divide the
product by 703. The quotient is 1722 and a remain¬
der of 292, i.e. the ctvctmas. Subtract the quotient from
the upper number, and the remainder, 108,318, repre¬
sents the civil days.
This method is to be amended in the following way : Emendation
You must know that between the epoch of the era here method.
used and the first of Sha'ban, here adopted as a date,
there have elapsed 25,958 days, i.e. 876 Arabic months,
or seventythree years and two months. If we further
