#!/bin/sh
# yeardays
# return the number of days in a year
# usage yeardays yyyy

# if there is no argument on the command line, then assume that a
# yyyy is being piped in

if [ $# = 0 ]
then
read y
else
y=$1
fi

# a year is a leap year if it is even divisible by 4
# but not evenly divisible by 100
# unless it is evenly divisible by 400

# if it is evenly divisible by 400 it must be a leap year
a=`expr $y % 400`
if [ $a = 0 ]
then
echo 366
exit
fi

#if it is evenly divisible by 100 it must not be a leap year
a=`expr $y % 100`
if [ $a = 0 ]
then
echo 365
exit
fi

# if it is evenly divisible by 4 it must be a leap year
a=`expr $y % 4`
if [ $a = 0 ]
then
echo 366
exit
fi

# otherwise it is not a leap year
echo 365