- One minus the number of the year is multiplied by 4.367. The figure assigned to the month concerned is added to the integer of the number obtained.
- When the total is divided by seven, the remainder shows the number of days from Friday.
- The figures assigned to the twelve Arabic months are relatively the first letters of the twelve capitalized words in the following mnemonic couplet:
**Hilmi, Be not Drifted by Hopeless Zeal of Earth!**

Jilting Damsel Was to the Zealous its Beauty’s Joy. - The succession of the twelve capital letters in the couplet is the same as the succession of the twelve Arabic months beginning with Muharram.
- As an example, let us find the twenty-ninth day of the month of Dhu’l-qa’da 1362: Let us multiply the number 1361 by 4.367; the answer is 5943. Now let us add two to this, –for the number assigned to Dhu’lqa’da is two–; the answer is 5945. If we divide this by seven the remainder is two. So, the first day of Dhu’l-qa’da is the second day beginning with Friday: It is Saturday. And the twenty-ninth day is again, naturally, Saturday. This method, discovered by Hüseyn Hilmi Işık ‘rahmatullâhi ta’âlâ ’alaih’.