A favorite difficulty, or supposed difficulty, which critics like to cite or have cited in the past years concerning the Qur'an is that, apparently to their thinking, the author of this book was ignorant because he advised the Muslims to follow the lunar instead of the solar year. The critics say the author was unaware of the difference in the length of years, that if one follows twelve lunar months one loses eleven days every year.

The author of the Qur'an was well aware of the distinction between the length of the solar year and the lunar year. In chapter eighteen, verse nine, it mentions three-hundred years and gives their equivalent as three-hundred and nine years. As it happens, three hundred solar years is equal to three -hundred and nine lunar years. Let us go back to my original scheme of the occurrence of words in the Qur'an. The Arabic word for 'month', shahar, will be found twelve times in the Qur'an. There are twelve months in a year. If we find twelve months, how many days should we expect to find? The word in Arabic is yaqum, and as it happens you will find that the word occurs three-hundred and sixty five time in the Qur'an.

As a matter of fact, the original issue which had me interest in looking up the occurrence of months and days was this distinction between the solar year and the lunar year. Well, for twenty-five centuries it has been known that the relative positions of the sun, moon and earth coincide every nineteen years. This was discovered by a Greek by the name of Meton, and it is called the 'Metonic' cycle. Knowing this, I looked again to the index for the word 'year', sanah and found, sure enough, that it occurs in the Qur'an nineteen times.