#!/bin/bash
# monthdays
# calculates the number of days in a month 
# usage monthdays [mon] [year]

# set the month and the year

m=$1
y=$2

# 30 days hath September etc.
case $m in
   1|3|5|7|8|10|12) echo 31 ; exit ;;
   4|6|9|11) echo 30 ; exit ;;
   *) ;;
esac

# except for month 2, which depends on whether the year is a leap year
# Use yeardays to get the number of days in the year and return a value
# accordingly.
diy=`yeardays $y`

case $diy in
   365) echo 28 ; exit ;;
   366) echo 29 ; exit ;;
esac