go语言-时间处理(time.Time)

一、Time的数据结构

type Time struct {
	// wall and ext encode the wall time seconds, wall time nanoseconds,
	// and optional monotonic clock reading in nanoseconds.
	//
	// From high to low bit position, wall encodes a 1-bit flag (hasMonotonic),
	// a 33-bit seconds field, and a 30-bit wall time nanoseconds field.
	// The nanoseconds field is in the range [0, 999999999].
	// If the hasMonotonic bit is 0, then the 33-bit field must be zero
	// and the full signed 64-bit wall seconds since Jan 1 year 1 is stored in ext.
	// If the hasMonotonic bit is 1, then the 33-bit field holds a 33-bit
	// unsigned wall seconds since Jan 1 year 1885, and ext holds a
	// signed 64-bit monotonic clock reading, nanoseconds since process start.
	wall uint64
	ext  int64

	// loc specifies the Location that should be used to
	// determine the minute, hour, month, day, and year
	// that correspond to this Time.
	// The nil location means UTC.
	// All UTC times are represented with loc==nil, never loc==&utcLoc.
	loc *Location
}

1. demo示例

time.Time()声明时，若未初始化则表示UTC时间，公元1年，1月，1日，0时，0分，0秒

	t1 := time.Time{}
	t2 := time.Now()
	t1Second := t1.Unix()
	t2Second := t2.Unix()
	fmt.Printf("t1:%v, t1Second:%v \n", t1, t1Second) // UTC时间1970-01-01 08:00:50的秒数为0,所以在此时间之前的为负值,且在int32范围之外
	fmt.Printf("t2:%v, t2Second:%v \n", t2, t2Second)
	fmt.Println("t2Second-t1Second=", t2Second-t1Second) // 所以会返回一个超大的值,已超过int32范围

demo：
```go
package main

import "fmt"
import "time"
func main (){
	start := time.Now()
	fmt.Println(start.Format(time.RFC850))

	fmt.Println("The time is", time.Now())

	//fmt.Println(time.Unix(time.Now().Unix(), 0).Format("2006-01-02 15:04:05"))
	var nowtime = time.Unix(time.Now().Unix(), 0).Format("2006-01-02 15:04:05")
	str := fmt.Sprintf("%s : The number of call", nowtime)
	fmt.Println(str)
}

2. golang打印英文格式时间日期

可以利用golang自带的format包来格式化日期格式
包的路径：goroot/src/time/format.go,以下是包的所包括格式内容

const (
    ANSIC       = "Mon Jan _2 15:04:05 2006"
    UnixDate    = "Mon Jan _2 15:04:05 MST 2006"
    RubyDate    = "Mon Jan 02 15:04:05 -0700 2006"
    RFC822      = "02 Jan 06 15:04 MST"
    RFC822Z     = "02 Jan 06 15:04 -0700" // RFC822 with numeric zone
    RFC850      = "Monday, 02-Jan-06 15:04:05 MST"
    RFC1123     = "Mon, 02 Jan 2006 15:04:05 MST"
    RFC1123Z    = "Mon, 02 Jan 2006 15:04:05 -0700" // RFC1123 with numeric zone
    RFC3339     = "2006-01-02T15:04:05Z07:00"
    RFC3339Nano = "2006-01-02T15:04:05.999999999Z07:00"
    Kitchen     = "3:04PM"
    // Handy time stamps.
    Stamp      = "Jan _2 15:04:05"
    StampMilli = "Jan _2 15:04:05.000"
    StampMicro = "Jan _2 15:04:05.000000"
    StampNano  = "Jan _2 15:04:05.000000000"
)

	start := time.Now()
	fmt.Println(start.Format(time.RFC850))