Walter's JokeBook
	"A Night Off"

So you don't feel like observing and want the night off? Let's look at what you are asking for...

There are 365 nights per year available for observing. There are 12 months of the year in which the moon uses up 13 nights, leaving 209 nights available. Since the skies are often cloudy, you have used up another 156 nights, leaving only 53 nights available. You spend 4 clear -20ºC nights a month indoors during the winter and that accounts for 24 nights, leaving only 29 nights. With clouds (nebulae?) of mosquitoes each summer, you have used up another 10 nights, leaving only 19 nights available for observing. You normally lose 6 nights to the Aurora Borealis (or Australis -- there's no escaping it!). This leaves you only 13 nights available for observing. Dew and frost claim 5 nights each year and social commitments 4, so your available observing time is down to 4 nights. Inevitably you have 3 nights of bad guiding and various kinds of equipment failure each year, which leaves only one night, and if you take that night off, you won't get any observing done this year!