return current month' days
return current month' days

return current month's number of days if $month is lesser than 1 or bigger than 12.
danvers/enrollment-tool,geomorillo/framework,XTRO123/framework,XTRO123/framework,LuckyCyborg/simple-mvc-framework,LuckyCyborg/framework,LuckyCyborg/simple-mvc-framework,XTRO123/framework,LuckyCyborg/simple-mvc-framework,danvers/enrollment-tool,nova-framework/framework,simple-mvc-framework/framework,simple-mvc-framework/framework,geomorillo/framework,LuckyCyborg/framework,danvers/enrollment-tool,nova-framework/framework,geomorillo/framework,LuckyCyborg/simple-mvc-framework