Happy Diwali

I kinda liked this photo which came across my radar - it's the big smile on the face of President Barack Obama, last Wednesday, lighting "the official White House "diya" to mark the celebration of Diwali, a Hindu festival that will be celebrated by Hindus, Jains and Sikhs around the world this weekend. A local Hindu priest from Maryland recited the mantra as Obama lighted the lamp." [credit: SAJAForum]

Anyways, we're West London bound to my mother's for the Diwali weekend. Not that I am of the religious variety, but the children enjoy it, just like Christmas, and I appreciate the beauty and history of it all. Hubby gets to eat lots of Indian sweets and gets fussed over. The kids, hubby and me get to light a candle at the local gurdhwara (sikh temple) and I might get to find out the answer to that eternal question that's always puzzled me - what's the explanation for the amazing co-incidence of Hindus and Sikhs celebrating Diwali on exactly the same day but for totally different reasons? Can anyone enlighten me? (I can't ask my mum because I don't know how to say 'co-incidence' in Punjabi...)