Bhagwan Shiv is known for his compassion towards all. There is none who don’t get his protection when they call out his name with true devotion. Be it the call of the saving the world from the posinious Halhal or the call of Bhageeratha to bear the mighty Ganga river, he is always there at the beck and call of the needy. One such incident wherein he saved Chandra or the Moon God from disappearing and gave it a special status as his ornament is an interesting one on the base of which the Lunar calendar of our Sanatana Dharma was formed.
Brahma Ji created eleven Prajapatis who assisted him in creation of the universe. They were considered the children of Brahma Ji and consequently went on to become Brahma in the future. Among these Prajapatis, Daksh was very famous for his intellect and power. Daksh had twenty seven daughters who were the Nakshatras, or the stars apart from his elder daughter Sati, who was the consort of Bhagwan Shiv. Daksh gave his twenty seven daughters in marriage to Chandr, the moon god. Out of all the daughters, Rohini was the most beautiful one and Chandr began to be partial to her and neglected his other wives. This upset the other wives and they in grief, went and complained about their husband’s behaviour to their father Daksh. Listening to this, Daksh called upon Chandr and asked him to treat all his wives equally.
Chandr who was madly in love with Rohini refused to do that and said that his mind was set upon Rohini. Daksh was angry with Chandr on this, and he cursed Chandr to fade away and suffer from the Kshay disease which causes to the moon god to wither away. Chandr feels miserable for this curse and starts to wither away. The daughters feel bad for their husband’s plight and advice Chandr to seek refuge in Bhagwan Shiv, before he completely disappeared with the disease.
Chandr goes to Bhagwan Shiv and falls at his feet and seeks refugee. The Moon god had a great responsibility in controlling the tides, currents of the sea on which the rains depended, and thus life on Earth. The functioning of the universe would be in chaos if the moon withered away.
Understanding the importance of the moon god, and taking pity on his plight, Bhagwan Shiv provided him a place on his forehead. Gaining contact with Bhagwan Shiv, the moon god began to shine again.
However, as the curse of Daksh could not fail, the Moon God was altered of waxing for fifteen days of the month and waning for the other fifteen days of the month, thus forming the Amavasya and the Poornima dates in the Lunar calendar. It is believed that Moon god is closer to Rohini, his favourite wife during the waxing and fades away when he moves away from Rohini.
Bhagwan Shiv who adorned the Moon God came to be known as Chandrasekhar, meaning the one who adorns the moon as a crown. He is also called as Somnath, as the one who adorns moon as the jewel. Shiv is specially worshipped on the fourteenth day before Poornima, as it is believed to bring good fortune and regenerate life as how it was done for the Moon God. Worshipping Shiv on the Kartik Somvar, which happens to be the day of the moon hence has gained so much of significance too.