golang获取当前时间是第几周

func main() {

    l, _ := time.LoadLocation("Asia/Shanghai")

    startTime,_ := time.ParseInLocation("2006-01-02", "2018-12-22", l)

    endTime,_ := time.ParseInLocation("2006-01-02", "2019-05-17", l)

    datas := GroupByWeekDate(startTime, endTime)

    for _, d := range datas {

        fmt.Println(d)

    }

}

//判断时间是当年的第几周

func WeekByDate(t time.Time) string {

    yearDay := t.YearDay()

    yearFirstDay := t.AddDate(0, 0, -yearDay+1)

    firstDayInWeek := int(yearFirstDay.Weekday())

    //今年第一周有几天

    firstWeekDays := 1

    if firstDayInWeek != 0 {

        firstWeekDays = 7 - firstDayInWeek + 1

    }

    var week int

    if yearDay <= firstWeekDays {

        week =  1

    } else {

        week = (yearDay-firstWeekDays)/7 + 2

    }

    return fmt.Sprintf("%d第%d周", t.Year(), week)

}

type WeekDate struct {

    WeekTh    string

    StartTime time.Time

    EndTime   time.Time

}

// 将开始时间和结束时间分割为周为单位

func GroupByWeekDate(startTime, endTime time.Time) []WeekDate {

    weekDate := make([]WeekDate, 0)

    diffDuration := endTime.Sub(startTime)

    days := int(math.Ceil(float64(diffDuration / (time.Hour * 24))))+1

    currentWeekDate := WeekDate{}

    currentWeekDate.WeekTh = WeekByDate(endTime)

    currentWeekDate.EndTime = endTime

    currentWeekDay := int(endTime.Weekday())

    if currentWeekDay == 0 {

        currentWeekDay = 7

    }

    currentWeekDate.StartTime = endTime.AddDate(0, 0, -currentWeekDay+1)

    nextWeekEndTime := currentWeekDate.StartTime

    weekDate = append(weekDate, currentWeekDate)

    for i := 0; i <(days-currentWeekDay)/7; i++ {

        weekData := WeekDate{}

        weekData.EndTime = nextWeekEndTime

        weekData.StartTime = nextWeekEndTime.AddDate(0, 0, -7)

        weekData.WeekTh = WeekByDate(weekData.StartTime)

        nextWeekEndTime = weekData.StartTime

        weekDate = append(weekDate, weekData)

    }

    if lastDays := (days - currentWeekDay) % 7; lastDays > 0 {

        lastData := WeekDate{}

        lastData.EndTime = nextWeekEndTime

        lastData.StartTime = nextWeekEndTime.AddDate(0, 0, - lastDays)

        lastData.WeekTh = WeekByDate(lastData.StartTime)

        weekDate = append(weekDate, lastData)

    }

    return weekDate

}