As taught in Sefer Yetzirah, every day of the year is represented by three letters corresponding to its season, the month, and the day of the week.
We are taught in Sefer Yetzirah that the twenty-two letters of the Hebrew Alphabet — the twenty-two channels of Divine creative consciousness — divide into three categories:
- three Mother or Primary letters,
- seven Double letters,
- and twelve Simple or Elemental letters.
Each letter of these three categories relates (in one-to-one correspondence) to an individual element in each of the three general dimensions of created reality:
- space (עולם)
- time (שנה)
- soul (נפש)
3 Mother letters
In relation to the dimension of time, the three "Mother" letters correspond to the seasons of the year and are divided in the following manner:
- The summer (the three Hebrew months of Tamuz, Av, Elul), is represented by the letter shin (the letter of fire),
- the winter (the three Hebrew months of Tevet, Shevat, Adar) is represented by mem (the letter of water),
- and the two intermediate seasons of:
spring (the three Hebrew months of Nissan, Iyar, Sivan),
and fall (the three Hebrew months of Tishrei, Cheshvan, Kislev) are represented by alef (the letter of air).
7 double letters
The seven Double letters (double because they each represent two sounds, hard and soft) correspond to the seven days of the week, and are divided in the following manner:
- Sunday is represented by beit
- Monday by gimel
- Tuesday by dalet
- Wednesday by kaf
- Thursday by pei
- Friday by reish
- Saturday by tav
12 Simple or Elemental letters
The twelve remaining letters are categorized as Simple or Elemental and correspond to the twelve Hebrew months of the year, as follows: