There can be no fixed answer. It will vary from person to person, and from situation to situation. The guideline must be what Allah, after taking into account all human factors, has said: 'Read whatever you can with ease' (al-Muzzammil 73:20).

The practice of the Companions and those who followed them varied considerably. Some used to finish the whole Qur'an in two months, some in one month, some in ten days, some in one week, some even in one day. You should, however, bear in mind the following Hadith as the governing criteria:

One who reads the Qur'an in less than three days does not understand it (Abu Da'ud, Tirmidhi).

Once, when Ibn 'Umar upon being asked by the Prophet, blessings and peace be on him, to read the Qur'an in one month insisted on doing so in less time, he told him: Read it in seven days and do not increase on this (Bukhari).

That the Qur'an is divided into 7 hizb (groups) and 30 juz' (parts) gives some indication of what is considered desirable.

In this respect al-Nawawi's advice is very sensible: One who can discover deeper meanings by contemplation should read less, similarly one who has to devote time in pursuits like education, affairs of government, or important tasks entrusted by Islam may read less (Kitab al-Adhkar).

The quantity of reading will very much depend on the purpose of reading. If you just want to spend time with the Qur'an, or get a quick overview, you may read much faster and, therefore, more. If you want to ponder and reflect, you may read much slower and, therefore, less. This is what al-Ghazali means when he quotes someone as saying 'I complete the reading of the Qur'an sometimes on every Friday, sometimes every month, sometimes every year. And (in one type of reading) I have been trying to complete it for the last thirty years but have not yet done so' (Ihya').

Under our present circumstances, I think, most of us should aim to finish a general reading of the whole Qur'an at least once every eight months. This should not take more than 5-15 minutes every day, depending on whether you understand the meaning directly or through a translation.

But, at least on a few occasions in your lifetime, you should also attempt to finish one reading in seven days. Or, in one month, especially in the month of Ramadan. Some time should also be devoted to reading slowly, with pondering and reflection, though not necessarily daily.