go指定分隔符格式化时间

一、代码

package main

import (
    "fmt"
    "strings"
    "strconv"
    "time"
)

// StrToIntMonth 字符串月份转整数月份
func StrToIntMonth(month string) int  {
    var data = map[string]int{
        "January"   : 0,
        "February"  : 1,
        "March"     : 2,
        "April"     : 3,
        "May"       : 4,
        "June"      : 5,
        "July"      : 6,
        "August"    : 7,
        "September" : 8,
        "October"   : 9,
        "November"  : 10,
        "December"  : 11,
    };
    return data[month];
}

// GetTodayYMD 得到以sep为分隔符的年、月、日字符串(今天)
func GetTodayYMD(sep string) string {
    now     := time.Now()
    year    := now.Year()
    month   := StrToIntMonth(now.Month().String())
    date    := now.Day()

    var monthStr string
    var dateStr string
    if month < 9 {
        monthStr = "0" + strconv.Itoa(month + 1)
    } else {
        monthStr = strconv.Itoa(month + 1)
    }

    if date < 10 {
        dateStr = "0" + strconv.Itoa(date)
    } else {
        dateStr = strconv.Itoa(date)
    }
    return strconv.Itoa(year) + sep + monthStr + sep + dateStr
}

// GetTodayYM 得到以sep为分隔符的年、月字符串(今天所属于的月份)
func GetTodayYM(sep string) string {
    now     := time.Now()
    year    := now.Year()
    month   := StrToIntMonth(now.Month().String())

    var monthStr string
    if month < 9 {
        monthStr = "0" + strconv.Itoa(month + 1)
    } else {
        monthStr = strconv.Itoa(month + 1)
    }
    return strconv.Itoa(year) + sep + monthStr
}

// GetYesterdayYMD 得到以sep为分隔符的年、月、日字符串(昨天)
func GetYesterdayYMD(sep string) string {
    now           := time.Now()
    today         := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.Local)
    todaySec      := today.Unix() //秒
    yesterdaySec  := todaySec - 24 * 60 * 60; //秒
    yesterdayTime := time.Unix(yesterdaySec, 0)
    yesterdayYMD  := yesterdayTime.Format("2006-01-02")
    return strings.Replace(yesterdayYMD, "-", sep, -1)
}

// GetTomorrowYMD 得到以sep为分隔符的年、月、日字符串(明天)
func GetTomorrowYMD(sep string) string {
    now           := time.Now()
    today         := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.Local)
    todaySec      := today.Unix() //秒
    tomorrowSec   := todaySec + 24 * 60 * 60; //秒
    tomorrowTime  := time.Unix(tomorrowSec, 0)
    tomorrowYMD   := tomorrowTime.Format("2006-01-02")
    return strings.Replace(tomorrowYMD, "-", sep, -1)
}

func main() {
    //当天
    res0:=GetTodayYMD("*")
    fmt.Println(res0)
    //本月
    res1:=GetTodayYM("-")
    fmt.Println(res1)
    //昨天
    res2:=GetYesterdayYMD(".")
    fmt.Println(res2)
    //明天
    res3:=GetTomorrowYMD(" ")
    fmt.Println(res3)
}

二、结果

2019*11*26
2019-11
2019.11.25
2019 11 27