What is Nyepi Day? And why are there no flights?

Today is Nyepi the Balinese 'Day of Silence' which is celebrated as part of Isakawarsa with tomorrow being Balinese New Years Day.  Although a Hindu festival, Nyepi is observed by all in Bali, a description of it follows

Observed from 6 a.m. until 6 a.m. the next morning, Nyepi is a day reserved for self-reflection, and as such, anything that might interfere with that purpose is restricted. The main restrictions are no lighting fires (and lights must be kept low); no working; no entertainment or pleasure; no traveling; and, for some, no talking or eating at all. The effect of these prohibitions is that Bali's usually bustling streets and roads are empty, there is little or no noise from TVs and radios, and few signs of activity are seen even inside homes. The only people to be seen outdoors are the Pecalang, traditional security men who patrol the streets to ensure the prohibitions are being followed.  Although Nyepi is primarily a Hindu holiday, non-Hindu residents of Bali observe the day of silence as well, out of respect for their fellow citizens. Even tourists are not exempt; although free to do as they wish inside their hotels, no one is allowed onto the beaches or streets, and the only airport in Bali remains closed for the entire day. The only exceptions granted are for emergency vehicles carrying those with life-threatening conditions and women about to give birth.

This effects the following flights to/from Australia today/tomorrow morning

KEY:

JQ - Jetstar

VA - Virgin Australia

GA - Garuda Indonesia

QZ - Indonesia AirAsia

320 - Airbus A320

73H - Boeing 737-8FE(W)

333 - Airbus A330-300

332 - Airbus A330-200

100 - Fokker F100

788 - Boeing 787-8