Whoever had a Wet Dream in the Daytime during Ramadhan
Question :
If the fasting person has a wet dream in the daytime during Ramadhan, does that invalidate his fast or not? Also, is he obligated to perform complete bathing immedi ately?
Answer:
Wet dreams do not invalidate the fast, because it is not done by the choice of the fasting person. He must perform complete bathing as he would for sexual impurity. If he had the wet dream after the Fajr prayer and he delayed bathing until the time of the Zuhr prayer, there is no harm in that. Likewise, if a man has sex with his wife at night and he does not bathe until after the Fajr time enters, there is no sin on him for that. Verily, it has been confirmed from the Prophet that he would wake up in the morning in a state of sexual impurity, then he would bathe and fast. The same applies to the menstruating woman and the woman with post childbirth bleeding. If they become pure during the night and they do not bathe until after the Fajr time enters, there is no harm in that and their fast is correct. However, it is not permissible for them or the sexual impure person to delay bathing or the prayer until sunrise. Rather it is obligatory on all of them to make haste in bathing before sunrise so that they can offer the prayer in its time. The man must make haste in bathing from sexual impurity before the Fajr prayer so that he can perform the prayer in congregation, And Allâh is the Giver of success.
Source:
Ash-Shaykh Ibn Baz
Fatawa Islamiyah, Vol. 3 Page 279