time1 := "2015-03-20 08:50:29"
time2 := "2015-03-21 09:04:25"
//先把时间字符串格式化成相同的时间类型
t1, err := time.Parse("2006-01-02 15:04:05", time1)
t2, err := time.Parse("2006-01-02 15:04:05", time2)
if err == nil  t1.Before(t2) {
  //处理逻辑
  fmt.Println("true")
}