time.AddDate（）不适用于仅解析时间，并将日期设置为今天？

Question

https://play.golang.org/p/O1FWb9O97ld

func main() {
    //const longForm = "Jan 2, 2006 at 3:04pm (MST)"
    t1, _ := time.Parse("03:04:05", "12:03:30")
    fmt.Printf("current date time %v\n", t1)
    now := time.Now().UTC()
    t1.AddDate(now.Year(), int(now.Month()), now.Day())
    fmt.Printf("current date time %v", t1)
}

输出 current date time 0000-01-01 12:03:30 +0000 UTC current date time 0000-01-01 12:03:30 +0000 UTC

基本上我只解析时间但想要添加今天的日期。但是在调用time.AddDate（）

后没有任何改变

Answer 1

AddDate不会改变接收器的值（接收器不是指针）。您需要将值分配给某些内容，例如

t1 = t1.AddDate(now.Year(), int(now.Month())-1, now.Day()-1)

我还从1和1开始的月份和日期减1。

这可能是做你想做的更好的方法：

func main() {
    //const longForm = "Jan 2, 2006 at 3:04pm (MST)"
    t1, _ := time.Parse("03:04:05", "12:03:30")
    fmt.Printf("current date time %v\n", t1)
    hour, min, sec := t1.Clock()
    now := time.Now().UTC()
    year, month, day := now.Date()
    t1 = time.Date(year, month, day, hour, min, sec, 0, time.UTC)
    fmt.Printf("current date time %v\n", t1)
}