Millions of years ago there was no light on earth.It was dark 24 hours a day.The people had heard about the god of dark and the story was that his mother had been the goddess of light but she had died and there was no light from that day on. The god of dark was very sad and angry but his mother told him there would be light again only if he married the other goddess of light.
So he travelled all around the world for 3 years. He searched everywhere but he did not know what to search for. He had given up all hope and decided that the earth was always going to be dark.
Years later some visitors came and they went across all the village.They came to a part were the god of dark was sitting. One of the visitors stepped forward, "Are you the god of dark?" she asked.
"YES I am!" he replied quite shocked.
The next day they planned a wedding.The god of dark said we need to get married so we can share dark and light. So they did it was a lovely wedding and they shared dark and light - 12 hours of light and 12 hours of dark and that's how we have Day and Night.