The time interval

const (
    Nanosecond  Duration = 1
    Microsecond          = 1000 * Nanosecond
    Millisecond          = 1000 * Microsecond
    Second               = 1000 * Millisecond
    Minute               = 60 * Second
    Hour                 = 60 * Minute
)

	now := time.Now()        //  Get the current time  
	timestamp := now.Unix()  //  Second timestamps  1658223718
	milli := now.UnixMilli() //  Millisecond time stamp  Go1.17+ 1658223718098
	micro := now.UnixMicro() //  Microsecond timestamps  Go1.17+ 1658223718098170
	nano := now.UnixNano()   //  Nanosecond time stamp  1658223718098170800
	fmt.Println(timestamp, milli, micro, nano)   

The time zone

// To create a time object, you need to specify a location .
// Common locations are  time.Local（ Local time ）  and  time.UTC（UTC Time ）.
//timeInLocal := time.Date(2009, 1, 1, 20, 0, 0, 0, time.Local) //  System local time 
// Beijing time. （ East eight ） Than UTC Good morning! 8 Hours 
// timezoneDemo  Time zone example 
func timezoneDemo() {
    
	//  There is no daylight saving time in China , Use a fixed 8 Hours of UTC time difference .
	//  For many other countries, summer time needs to be considered .
	secondsEastOfUTC := int((8 * time.Hour).Seconds())
	// FixedZone  Return always use the given area name and offset (UTC  East Second ) Of  Location.
	beijing := time.FixedZone("Beijing Time", secondsEastOfUTC)

	//  If the current system time zone database , You can load a location to get the corresponding time zone 
	//  for example , Load the time zone of New York 
	newYork, err := time.LoadLocation("America/New_York") // UTC-05:00
	if err != nil {
    
		fmt.Println("load America/New_York location failed", err)
		return
	}
	fmt.Println()
	//  Load the time zone of Shanghai 
	//shanghai, err := time.LoadLocation("Asia/Shanghai") // UTC+08:00
	//  Load the time zone of Tokyo 
	//tokyo, err := time.LoadLocation("Asia/Tokyo") // UTC+09:00

	//  To create a time object, you need to specify a location . Common locations are  time.Local（ Local time ）  and  time.UTC（UTC Time ）.
	//timeInLocal := time.Date(2009, 1, 1, 20, 0, 0, 0, time.Local) //  System local time 
	timeInUTC := time.Date(2009, 1, 1, 12, 0, 0, 0, time.UTC)
	sameTimeInBeijing := time.Date(2009, 1, 1, 20, 0, 0, 0, beijing)
	sameTimeInNewYork := time.Date(2009, 1, 1, 7, 0, 0, 0, newYork)

	//  Beijing time. （ East eight ） Than UTC Good morning! 8 Hours , So the above two times seem to be different 8 Hours , But it means the same time 
	timesAreEqual := timeInUTC.Equal(sameTimeInBeijing)
	fmt.Println(timesAreEqual)

	//  New York （ West five ） Than UTC On the evening of 5 Hours , So the above two times seem to be different 5 Hours , But it means the same time 
	timesAreEqual = timeInUTC.Equal(sameTimeInNewYork)
	fmt.Println(timesAreEqual)
}

var timeLayout = "2006-01-02 15:04:05"

Remove the time part from the string date （ That is, hours, minutes and seconds ）

func DateStringWipeOffTime(date string) string {
    
	date = strings.TrimPrefix(date, " ")
	date = strings.TrimSuffix(date, " ")
	if strings.Contains(date, " ") {
    
		i := strings.Index(date, " ")
		date = date[:i]
		return date
	}
	return date
}

Add the time part to the string date （ Default part ）

func DateStringAddTime(date string) string {
    
	date = strings.TrimPrefix(date, " ")
	date = strings.TrimSuffix(date, " ")
	if strings.Contains(date, " ") {
    
		return date
	}
	date = date + " 00:00:00"
	return date
}

Get the local time according to the string date （int64 type ）

func StringToLocationInt64(date string) int64 {
    
	loc, _ := time.LoadLocation("Local")
	if strings.Contains(date, " ") {
    
		dateTime, _ := time.ParseInLocation(timeLayout, date, loc)
		dateTimeInt := dateTime.Unix()
		return dateTimeInt
	}
	dateTime, _ := time.ParseInLocation("2006-01-02", date, loc)
	dateTimeInt := dateTime.Unix()
	return dateTimeInt
}

String date to time.Time Don't be part of the hour, minute and second

func StringToDateWithOutTime(date string) string {
    
	dateTimeInt := StringToLocationInt64(date)
	result := time.Unix(dateTimeInt, 0).Format("2006-01-02")
	return result
}

String date to time.Time, Keep the part of hours, minutes and seconds

func StringToDateWithInTime(date string) string {
    
	dateTimeInt := StringToLocationInt64(date)
	result := time.Unix(dateTimeInt, 0).Format(timeLayout)
	return result
}

Date calculation , Increase the specified number of days , Do not keep hours, minutes and seconds

func DateAddDayWhitOutTime(date string, days int) string {
    
	dateTimeInt := int(StringToLocationInt64(date))
	oneDay := 86400
	addingDays := oneDay * days
	dateTimeInt += addingDays
	dateTimeString := time.Unix(int64(dateTimeInt), 0).Format("2006-01-02")
	return dateTimeString
}

Date calculation , Increase the specified number of days , Reserved hours, minutes and seconds

func DateAddDayWhitInTime(date string, days int) string {
    
	dateTimeInt := int(StringToLocationInt64(date))
	oneDay := 86400
	addingDays := oneDay * days
	dateTimeInt += addingDays
	dateTimeString := time.Unix(int64(dateTimeInt), 0).Format("2006-01-02 15:04:05")
	return dateTimeString
}

Timer

func tickDemo() {
    
	ticker := time.Tick(time.Second) // Define a 1 Second interval timer 
	for i := range ticker {
    
		fmt.Println(i)// Tasks that are performed every second 
	}
}