Ans.15: It is obligatory on every Muslim that he should pray every prayer on its time and it is not permissible for him to delay all the prayers until their last permissible time except for the one who has an excuse such as sleep or forgetfulness. So if a person misses a prayer due to sleep or forgetfulness, then he should pray it as soon as he wakes up or as soon as he remembers, accordingly this is based on the hadith of the Prophet (sallallahu ‘alayhi wa sallam) ‘whoever forgets a prayer then he should pray it when he remembers.’ Also, the one who is sick is allowed to combine the dhuhur and ‘asr prayer at the earlier time of 'Asr, and the maghrib and ‘isha prayer at the earlier time of 'Isha. If he is so sick that he misses them further, then he should pray as it is. As for the times which are dharurah (necessary) then for the ‘Asr prayer it is just before the sunset, and for the ‘Isha prayer, it is the middle of the night. Here the designated time of the prayer has ended and the time of dharurah (necessity) comes in, and Allaah Knows Best. The Fajr prayer, its time of dharurah, is just before the sunrise based on the hadith of the Prophet (sallallahu ‘alayhi wa sallam) who said, ‘Whoever catches a rak’ah (standing) of the prayer before the sun has risen then he has caught the prayer.’