Go语言时间格式化

package main

import (
"fmt"
"time"
)

func main() {
fmt.Println(time.Now().Format("2006-01-02 15:04:05"))          // -->2017-04-17 17:21:33
fmt.Println(timFormat("2017-12-24 23", "yyyy-MM-dd HH:mm:ss")) // -->2017-12-24 23:00:00
}

/*
将输入的date按照指定的partten格式化
@version 1.0 目前只支持正常的格式，其余变态格式暂不支持
如：yyyy,yyyy-MM,yyyy-MM-dd,yyyy-MM-dd HH,yyyy-MM-dd HH:mm,yyyy-MM-dd HH:mm:ss
@date string 要被格式化的日期
@partten stirng 指定格式
@author wangdy
return 返回格式化后的日期
*/
func timFormat(date, partten string) string {
var ptnLength = len(partten)
var dateLength = len(date)
returnStr := date
switch partten {
case partten:
if ptnLength <= dateLength {
return Substr(date, 0, ptnLength)
} else {
var chaLen = ptnLength - dateLength
if dateLength == 4 {
if chaLen == 3 {
returnStr += "-01"
return returnStr
} else if chaLen == 6 {
returnStr += "-01-01"
return returnStr
} else if chaLen == 9 {
returnStr += "-01-01 00"
return returnStr
} else if chaLen == 12 {
returnStr += "-01-01 00:00"
return returnStr
} else if chaLen == 15 {
returnStr += "-01-01 00:00:00"
return returnStr
}
} else if dateLength == 7 {
if chaLen == 3 {
returnStr += "-01"
return returnStr
} else if chaLen == 6 {
returnStr += "-01 00"
return returnStr
} else if chaLen == 9 {
returnStr += "-01 00:00"
return returnStr
} else if chaLen == 12 {
returnStr += "-01 00:00:00"
return returnStr
}
} else if dateLength == 10 {
if chaLen == 3 {
returnStr += " 00"
return returnStr
} else if chaLen == 6 {
returnStr += " 00:00"
return returnStr
} else if chaLen == 9 {
returnStr += " 00:00:00"
return returnStr
}
} else if dateLength == 13 {
if chaLen == 3 {
returnStr += ":00"
return returnStr
} else if chaLen == 6 {
returnStr += ":00:00"
return returnStr
}
} else if dateLength == 16 && chaLen == 3 {
returnStr += ":00"
return returnStr
}
return "xxxxxxxxxx" + date
}
default:
fmt.Println("it's default case!")
return date
}
}

/*
按照格式截取字符串
@str string 要被截取的源字符串
@start int 开始索引，从0开始
@length int 要截取的长度
@author wangdy
return 返回截取后字符串
*/
func Substr(str string, start, length int) string {
rs := []rune(str)
rl := len(rs)
end := 0

if start < 0 {
start = rl - 1 + start
}
end = start + length

if start > end {
start, end = end, start
}

if start < 0 {
start = 0
}
if start > rl {
start = rl
}
if end < 0 {
end = 0
}
if end > rl {
end = rl
}
return string(rs[start:end])
}