Hebrew date, Gregorian Date, or absolute (R.D.) day
number. The function returns the same DafPage for any day
of the same week; the dafWeeklySunday calendar registered with
DailyLearning exposes only the Sunday occurrence.
A DafPage for that week (name + blatt). Never
null once the cycle has begun.
Calculates the Daf-a-Week Talmud page for the given date.
In this slower schedule the same daf is studied for an entire week; one full cycle through the Babylonian Talmud takes ~52 years. The cycle began on Sunday, 6 March 2005 (25 Adar I 5765).