Originally, Hindu marriages were always held in daytime. As per Vedic knowledge and Bhagavad Gita, auspicious time is in Uttarayana, before full moon, in daytime and near agni and light. Medically, you are more mentally positive during this period. Marriage were shifted in the night only during a particular era a few hundred year back when kings of that era were ruthless and used to pickup young good looking women to spend night with them. To escape from them, people started getting their doctors married in night time so that their daughter is not divulged to the king’s soldier.