各位大侠好啊，现在要将每天的24小时，按两小时为一段进行划分，把量变为dummy值，怎么做到呀？我直接采用减法，大家帮看看啊：
if trade_time > 00:00:00 and trade_time < 02:00:00 then tradetime1 = 1;
    else tradetime1 = 0;
  if trade_time > 02:00:00 and trade_time < 04:00:00 then tradetime2 = 1;
    else tradetime2 = 0;
  if trade_time > 04:00:00 and trade_time < 06:00:00 then tradetime3 = 1;
    else tradetime3 = 0;
  if trade_time > 06:00:00 and trade_time < 08:00:00 then tradetime4 = 1;
    else tradetime4 = 0;
  if  trade_time > 08:00:00 and trade_time < 10:00:00 then tradetime5 = 1;
    else tradetime5 = 0;
    if  trade_time > 10:00:00 and trade_time < 12:00:00 then tradetime6 = 1;
    else tradetime6 = 0;
    if trade_time > 12:00:00 and trade_time < 14:00:00 then tradetime7 = 1;
    else tradetime7 = 0;
  if trade_time > 14:00:00 and trade_time < 16:00:00 then tradetime8 = 1;
    else tradetime8 = 0;
  if trade_time > 16:00:00 and trade_time < 18:00:00 then tradetime9 = 1;
    else tradetime9 = 0;
  if trade_time > 18:00:00 and trade_time < 20:00:00 then tradetime10 = 1;
    else tradetime10 = 0;
  if  trade_time > 20:00:00 and trade_time < 22:00:00 then tradetime11 = 1;
    else tradetime11 = 0;
    if  trade_time > 22:00:00 and trade_time < 24:00:00 then tradetime12 = 1;
    else tradetime12 = 0;
运行出现错误，怎么实现这个呢？非常感谢大家啊