判断上学和放假的demo

    var today = new Date();
    var xq = today.getDay();
    var Now = today.getHours();

    if (xq >= 1 && xq <= 6) {
        document.write("今天上课" + "<br>")
    }
    ;
    if (xq === 0) {
        document.write("今天放假")
    } else {
        if (Now >= 9 && Now < 12) {
            document.write("现在是上课时间")
        }
        ;
        if (Now >= 12 && Now < 14) {
            document.write("现在是下课时间")
        }
        ;
        if (Now >= 14 && Now < 18) {
            document.write("现在是上课时间")
        }
        ;
        if (Now < 9 ) {
            document.write("现在还没到上课时间")
        }
        ;
        if (Now >= 18) {
            document.write("现在是放学时间")
        }
    }