go - go语言中的时间转换问题

Question

我正在尝试了解 Go 语言中时间转换的问题。这是代码示例:

package main

import (
    "fmt"
    "time"
)

func unix2Str(ts int64) string {
    const layout = "20060102"
    t := time.Unix(ts, 0)
    return t.Format(layout)
}

func unixTime(ts string) int64 {
    const layout = "20060102"
    t, err := time.Parse(layout, ts)
    if err != nil {
            fmt.Println(err)
            return 0
    }
    return t.Unix()
}
func main() {
    ts1 := "20110320"
    ts2 := "20110321"

    ut1 := unixTime(ts1)
    ut2 := unixTime(ts2)

    fmt.Println(ts1, ut1, unix2Str(ut1))
    fmt.Println(ts2, ut2, unix2Str(ut2))
}

它打印以下输出:

20110320 1300579200 20110319
20110321 1300665600 20110320

但是由于我进行了从字符串格式到 Unix 格式的转换并反向转换，所以我希望字符串格式的日期得到相同的结果。但事实并非如此。事实上，打印的 unix 时间 1300579200 在 python 中转换为我开始使用的原始日期，例如

>>> time.strftime("%Y%m%d", time.gmtime(1300579200))
'20110320'

这是 Go 代码中的错误还是我遗漏了什么？

Answer 1

这是因为您本地的时区和 UTC 之间存在差异。 Parse 返回 UTC 时间，Unix 返回本地时间。例如，

package main

import (
    "fmt"
    "time"
)

func unix2Str(ts int64) string {
    const layout = "20060102"
    t := time.Unix(ts, 0)
    fmt.Println(t)
    return t.Format(layout)
}

func unixTime(ts string) int64 {
    const layout = "20060102"
    t, err := time.Parse(layout, ts)
    if err != nil {
        fmt.Println(err)
        return 0
    }
    fmt.Println(t)
    return t.Unix()
}

func main() {
    ts1 := "20110320"
    ts2 := "20110321"

    ut1 := unixTime(ts1)
    ut2 := unixTime(ts2)

    fmt.Println(ts1, ut1, unix2Str(ut1))
    fmt.Println(ts2, ut2, unix2Str(ut2))
}

输出:

2011-03-20 00:00:00 +0000 UTC
2011-03-21 00:00:00 +0000 UTC
2011-03-19 20:00:00 -0400 EDT
20110320 1300579200 20110319
2011-03-20 20:00:00 -0400 EDT
20110321 1300665600 20110320

---

func Parse

func Parse(layout, value string) (Time, error)

Parse parses a formatted string and returns the time value it represents. The layout defines the format by showing how the reference time, defined to be

Mon Jan 2 15:04:05 -0700 MST 2006

would be interpreted if it were the value; it serves as an example of the input format. The same interpretation will then be made to the input string.

In the absence of a time zone indicator, Parse returns a time in UTC.

---

func Unix

func Unix(sec int64, nsec int64) Time

Unix returns the local Time corresponding to the given Unix time, sec seconds and nsec nanoseconds since January 1, 1970 UTC.