Having Intercourse with One's Spouse During Ramadan
http://www.islamonline.net/
As far as Islamic Shari`ah is concerned, a Muslim is allowed to have
intercourse with his or her spouse after breaking the fast and until
dawn (the time of abstention from food, drink, and gratifications).
However, one who is fasting should never overstep the boundaries of
fasting by having intercourse with his or her spouse while fasting.
In his response to your question, Sheikh Ahmad Kutty, a senior
lecturer and Islamic scholar at the Islamic Institute of Toronto,
Ontario, Canada, states the following:
While it is forbidden to establish any conjugal relations with one’s
spouse while one is fasting during the day, one is certainly allowed to
do so during the night until the arrival of dawn (i.e., fajr).
Allah says:
“It is made lawful for you to go to your wives (in sexual relations)
on the night of the fast. They are a garment for you and you are a
garment for them. Allah knows that you were deceiving yourself in this
respect and He has turned in mercy towards you and pardoned you.
Therefore you may now have intercourse with them and seek what Allah has
ordained for you. Eat and drink until the white thread (of dawn) becomes
distinct to you from the black thread (of night)” (Al-Baqarah 2:187).
In short, we are allowed to enjoy intimate sexual relations after
breaking the fast throughout the night until the time of abstention from
food, drink, and gratifications (i.e. when the time of fajr arrives).
Excerpted with slight modifications from: www.islam.ca.