Incidentally, if you have a specific probability for an event occurring in 1 out of 365 days, say, or not occurring at all, you could try to calculate exactly what probability to give it occurring in the rest of the year (considering that it's August): http://www.xamuel.com/hope-function/ / http://www.gwern.net/docs/1994-falk

(Actually calculating the new probability is left as an exercise for the reader.)