section_path: Components/Weeks/Days of week of holidays
section_name: Days of week of holidays
paragraph_text: Days of week of holidays
  
  Jewish holidays can only fall on the weekdays shown in the following table:
  
  The period from 1 Adar (or Adar II, in leap years) to 29 Marcheshvan contains all of the festivals specified in the Bible (Purim, Passover, Shavuot, Rosh Hashanah, Yom Kippur, Sukkot, and Shemini Atzeret). The lengths of months in this period are fixed, meaning that the day of week of Passover dictates the day of week of the other Biblical holidays. However, the lengths of the months of Marcheshvan and Kislev can each vary by a day (due to the Rosh Hashanah postponement rules which are used to adjust the year length). As a result, the holidays falling after Marcheshvan (starting with Chanukah) can fall on multiple days for a given row of the table.
  
  A common mnemonic is " לא אד"ו ראש, ולא בד"ו פסח ", meaning: "Rosh HaShana cannot be on Sunday, Wednesday or Friday, and Passover cannot be on Monday, Wednesday or Friday" with each day's numerical equivalent, in gematria, is used, such that א' = 1 = Sunday, and so forth. From this rule, every other date can be calculated by adding weeks and days until that date's possible day of the week can be derived.