Code
private void checkOnWork()
    {
        /**********************************************
         * 正常上班时间段 7:00 <= onTime <= 8:30      *
         * 迟到时间段     8:30 < lateTime <= 10:00    *
         * 矿工时间段     10:00 < absentTime <= 12:00 *
         * 正常下班时间段 17:30 <= goTime <= 18:00    *
         * 早退时间段     12:00 < earlyTime < 17:30   *
         * 加班时间段     18:00 < overTime < 7:00     *
         **********************************************/

        string dateTimeNow = DateTime.Now.ToLongTimeString();//获取当前时间 格式=9:10:57
        DateTime timeNow = DateTime.Parse(dateTimeNow);//格式转换
        //声明时间段变量
        DateTime time700 = DateTime.Parse("7:00:00");
        DateTime time830 = DateTime.Parse("8:30:00");
        DateTime time1000 = DateTime.Parse("10:00:00");
        DateTime time1200 = DateTime.Parse("12:00:00");
        DateTime time1730 = DateTime.Parse("17:30:00");
        DateTime time1800 = DateTime.Parse("18:00:00");
        //上班打卡
        if (time700 <= timeNow <= time1200)
        {
            if (time700 <= timeNow <= time700)
            {
                Label1.Text = "正常上班";
            }
            else if (time830 < timeNow <= time1000)
            {
                Label1.Text = "迟到";
            }
            else if (time1000 < timeNow <= time1200)
            {
                Label1.Text = "旷工";
            }
        }
        //下班打卡
        else if (time1200 < timeNow < time700)
        {
            if (time1730 <= timeNow <= time1800)
            {
                Label1.Text = "正常下班";
            }
            else if (time1200 < timeNow < time1730)
            {
                Label1.Text = "早退";
            }
            else if (time1800 < timeNow < time700)
            {
                Label1.Text = "加班";
            }
        }
    }

Code
错误    1    运算符“<=”无法应用于“bool”和“System.DateTime”类型的操作数    C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\checkwork\Default.aspx.cs    77    13    C:\\checkwork\
错误    2    运算符“<=”无法应用于“bool”和“System.DateTime”类型的操作数    C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\checkwork\Default.aspx.cs    79    17    C:\\checkwork\
错误    3    运算符“<=”无法应用于“bool”和“System.DateTime”类型的操作数    C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\checkwork\Default.aspx.cs    83    22    C:\\checkwork\
错误    4    运算符“<=”无法应用于“bool”和“System.DateTime”类型的操作数    C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\checkwork\Default.aspx.cs    87    22    C:\\checkwork\
错误    5    运算符“<”无法应用于“bool”和“System.DateTime”类型的操作数    C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\checkwork\Default.aspx.cs    93    18    C:\\checkwork\
错误    6    运算符“<=”无法应用于“bool”和“System.DateTime”类型的操作数    C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\checkwork\Default.aspx.cs    95    17    C:\\checkwork\
错误    7    运算符“<”无法应用于“bool”和“System.DateTime”类型的操作数    C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\checkwork\Default.aspx.cs    99    22    C:\\checkwork\
错误    8    运算符“<”无法应用于“bool”和“System.DateTime”类型的操作数    C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\checkwork\Default.aspx.cs    103    22    C:\\checkwork\

Code
        DateTime dateTime1 = DateTime.Parse("8:30:00");        
        string nowTime = DateTime.Now.ToLongTimeString();
        DateTime dateTime2 = DateTime.Parse(nowTime);
        if (dateTime1 <= dateTime2)
        {
            TimeSpan timeSpan = dateTime2 - dateTime1;
            Label1.Text = timeSpan.ToString();
        }
        else
        {
            Label1.Text = "正常打卡";
        }