The fast runs from sunrise to moonrise, roughly twelve hours without food or water. Nothing about that is offered here as good for the body: it is a devotional undertaking, and anyone pregnant, nursing, diabetic or on daily medication should consult their own doctor before keeping it. What is worth noticing is the timing - Karthika Krishna Chaturthi sits in the clear, cool fortnight after the monsoon, and the moon it waits for rises early enough that the fast breaks at a sociable hour rather than deep in the night.