A'isha reported that when the Messenger of Allah ( صلی اللہ علیہ وسلم ) decided upon doing any act, he continued to do it, and when he slept at night or fell sick he observed twelve rak'ahs during the daytime. I am not aware of Allah's Messenger ( صلی اللہ علیہ وسلم ) observing prayer during the whole of the night till morning, or observing fast for a whole month continuously except that of Ramadan.