Tired of Working?

I saw this poster on the door of my PGDE professor when I went to deliver my CNY card to her. She was at a meeting but that gave me time to read the poster carefully. It made me laugh. :) Somehow I don't feel so tired anymore. :)

Here is the text in full (as it might be too small to read from the image)

Tired of Working? 
The year is made up of 365 days each having 
24 hours, 12 of which are night time hours
which add up to a total of 182 days.

This leaves you with 183 days to work minus
52 Sundays which leaves you 131 days to work
minus another 52 Saturdays which leaves you
79 days to work.

3 hours each day are set aside for eating and 
1 hour for bathing, going to toilet which adds
up to 60 days, which leaves you only 19 days
for working.

You are entitled to 14 days for your vacation 
which meansyou have 5 days left for your work
minus 4 days you usually take off due to illness 
or other emergencies, which leaves you 
only ONE day to work, which happens to be
Labour Day which is a holiday.

SO, WHY ARE YOU TIRED?