Adding click handler to multiple IDs
You should add a class to all elements, something like .day, and then use that class in your code:

$('.day').click(function() {
    if ($(this).hasClass("active")){
        $(this).switchClass( "active", "inactive", 200, "easeInOutQuad" );
        $(this).parent().find('.miniTime').prop('disabled', true);
    } else {
        $(this).switchClass( "inactive", "active", 200, "easeInOutQuad" );
        $(this).parent().find('.miniTime').prop('disabled', false);
    }
    $(this).find('input').prop('checked', function( foo, oldValue ) {return !oldValue});
});


Another way would be:

$('#Monday, #Tuesday, #Wendnesday').click(function() {
    if ($(this).hasClass("active")){
        $(this).switchClass( "active", "inactive", 200, "easeInOutQuad" );
        $(this).parent().find('.miniTime').prop('disabled', true);
    } else {
        $(this).switchClass( "inactive", "active", 200, "easeInOutQuad" );
        $(this).parent().find('.miniTime').prop('disabled', false);
    }
    $(this).find('input').prop('checked', function( foo, oldValue ) {return !oldValue});
});