As per Astrological point of view having sex in daytime should avoid if the couple are considered for expecting an issue.And the best time of intercourse is late night around 2 am to 4 or 4 :30 am for an good, honest, powerful and spiritually upgraded issue.There are so many arguments or controversy behind it but most popular concept is that during the time of late night or before the dawn the monk and saint are chanting Mantras to pray the almighty and a holy atmosphere are created and during this time good spirit or soul came to the earth for searching the womb for further human life.And it is believed that the child born resulting from intercourse during this period is become genius.