It"t high time you had your hair cut ,

该是理发的时间了
It is high time that+从句
该是...的时候了．从句后要用虚拟语气．
如:It is (high) time that we got home.我们该回家了．是我们该回家的时候了．
　It is (high) time that we went to bed.我们该睡觉了．是我们该睡觉的时候了．
希望我的回答能够帮到你,