When is prayer not allowed?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Abu Sa’eed Al-Khudri narrated that the Prophet said: “There is no prayer after Fajr until the sun rises, and there is no prayer after ‘Asr prayer until the sun sets.” [Al-Bukhari and Muslim]

On another occasion, ‘Uqbah Ibn 'Amr Aljuhany narrated: “There are three times during which the Prophet would forbid us from performing our prayers or burying our deceased: when the sun starts to rise until it has fully risen, when it is at its meridian, and when the sun starts setting until it has completely set.” [Muslim, An-Nasaa'i, Abu Daawood and others]

The Ahadeeth on this subject are many, and the main aim of the Prophet is to prevent his followers from praying after ‘Asr until the sun sets, and after the Fajr prayer until the sun rises, and between the time when the sun is starting to rise until it has done so.

The average time between when it starts rising until it has fully risen is said to be approximately fifteen minutes.
Also, from the times in which it is preferable not (detested) to perform prayers in, is the time when the sun reaches the culminating point (meridian); i.e., a few moments before the time of Thuhr prayer, and when the sun color starts to deepen; i.e., before dusk.

Imam An-Nawawi said: “The Ummah (Muslim nation) has all agreed upon that it is disliked to perform prayers without a good reason during these times, and they have also differed about the Nawaafil (supererogatory prayers) being performed during these times; e.g.: prayer of salutation to the mosque (Tahiyatul Masjid), prostration during the recitation of the Quran, ‘Eed prayer, eclipse prayer, funeral prayer, and when making up missed compulsory prayers.

Imam Ash-Shaafi'i and the scholars of his School have agreed that it is permissible without any dislikeability to perform the voluntary prayers that have a reason; to support their opinion they provide the above-mentioned Hadeeth and other Ahadeeth. The strongest opinion, which is based on the afore-mentioned Hadeeth and from them, is the Hadeeth which narrates that the Prophet prayed the Sunnah for the Thuhr prayer after the ‘Asr prayer.

These Ahadeeth, therefore, refer to the prayers which are not obligated.

Since, the Prophet allowed the missed Sunnah to be performed during these times, then the present Sunnah as well as the missed compulsory should obviously be given priority. The same also applies to the prayer over the deceased and other similar Sunnah prayers as we have mentioned earlier.

This view is of a strong basis, and different Ahadeeth are put into consensus based on this one.

Imam Abu-Haneefah and others have gone as far as to preventing any type of prayer during these times apart from the prescribed prayer of that time. They have given proof by bringing forth a majority of Ahadeeth, that have been mentioned and the first opinion is the strongest of proofs.

Allah knows best.