# Datetime

Package datetime supports date and time format and compare.

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## Source:

[https://github.com/duke-git/lancet/blob/v1/datetime/datetime.go](https://github.com/duke-git/lancet/blob/v1/datetime/datetime.go)

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## Usage:

```go
import (
    "github.com/duke-git/lancet/datetime"
)
```

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## Index

-   [AddDay](#AddDay)
-   [AddHour](#AddHour)
-   [AddMinute](#AddMinute)
-   [AddYear](#AddYear)
-   [BeginOfMinute](#BeginOfMinute)
-   [BeginOfHour](#BeginOfHour)
-   [BeginOfDay](#BeginOfDay)
-   [BeginOfWeek](#BeginOfWeek)
-   [BeginOfMonth](#BeginOfMonth)
-   [BeginOfYear](#BeginOfYear)
-   [EndOfMinute](#EndOfMinute)
-   [EndOfHour](#EndOfHour)
-   [EndOfDay](#EndOfDay)
-   [EndOfWeek](#EndOfWeek)
-   [EndOfMonth](#EndOfMonth)
-   [EndOfYear](#EndOfYear)
-   [GetNowDate](#GetNowDate)
-   [GetNowTime](#GetNowTime)
-   [GetNowDateTime](#GetNowDateTime)
-   [GetZeroHourTimestamp](#GetZeroHourTimestamp)
-   [GetNightTimestamp](#GetNightTimestamp)
-   [FormatTimeToStr](#FormatTimeToStr)
-   [FormatStrToTime](#FormatStrToTime)
-   [NewUnixNow](#NewUnixNow)
-   [NewUnix](#NewUnix)
-   [NewFormat](#NewFormat)
-   [NewISO8601](#NewISO8601)
-   [ToUnix](#ToUnix)
-   [ToFormat](#ToFormat)
-   [ToFormatForTpl](#ToFormatForTpl)
-   [ToIso8601](#ToIso8601)
-   [IsLeapYear](#IsLeapYear)
-   [BetweenSeconds](#BetweenSeconds)
-   [DayOfYear](#DayOfYear)
-   [IsWeekend](#IsWeekend)

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## Documentation

## Note:

1. 'format' string param in func FormatTimeToStr and FormatStrToTime function should be one of flows:

-   yyyy-mm-dd hh:mm:ss
-   yyyy-mm-dd hh:mm
-   yyyy-mm-dd hh
-   yyyy-mm-dd
-   yyyy-mm
-   mm-dd
-   dd-mm-yy hh:mm:ss
-   yyyy/mm/dd hh:mm:ss
-   yyyy/mm/dd hh:mm
-   yyyy-mm-dd hh
-   yyyy/mm/dd
-   yyyy/mm
-   mm/dd
-   dd/mm/yy hh:mm:ss
-   yyyy
-   mm
-   hh:mm:ss
-   mm:ss

### <span id="AddDay">AddDay</span>

<p>Add or sub days to time.</p>

<b>Signature:</b>

```go
func AddDay(t time.Time, day int64) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()
    after2Days := datetime.AddDay(now, 2)
    before2Days := datetime.AddDay(now, -2)

    fmt.Println(after2Days, before2Days)
}
```

### <span id="AddHour">AddHour</span>

<p>Add or sub hours to time.</p>

<b>Signature:</b>

```go
func AddHour(t time.Time, hour int64) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()
    after2Hours := datetime.AddHour(now, 2)
    before2Hours := datetime.AddHour(now, -2)

    fmt.Println(after2Hours, after2Hours)
}
```

### <span id="AddMinute">AddMinute</span>

<p>Add or sub minutes to time.</p>

<b>Signature:</b>

```go
func AddMinute(t time.Time, minute int64) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()
    after2Minute := datetime.AddMinute(now, 2)
    before2Minute := datetime.AddMinute(now, -2)

    fmt.Println(after2Minute, before2Minute)
}
```

### <span id="AddYear">AddYear</span>

<p>Add or sub year to the time.</p>

<b>Signature:</b>

```go
func AddYear(t time.Time, year int64) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()

	after1Year := datetime.AddYear(now, 1)
	diff1 := after1Year.Sub(now)

	before1Year := datetime.AddYear(now, -1)
	diff2 := before1Year.Sub(now)

	fmt.Println(diff1)
	fmt.Println(diff2)

	// Output:
	// 8760h0m0s
	// -8760h0m0s
}
```

### <span id="BeginOfMinute">BeginOfMinute</span>

<p>Return beginning minute time of day.</p>

<b>Signature:</b>

```go
func BeginOfMinute(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.BeginOfMinute(td)
    fmt.Println(bm) //2022-02-15 15:48:00 +0800 CST
}
```

### <span id="BeginOfHour">BeginOfHour</span>

<p>Return zero time of day.</p>

<b>Signature:</b>

```go
func BeginOfHour(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.BeginOfHour(td)
    fmt.Println(bm) //2022-02-15 15:00:00 +0800 CST
}
```

### <span id="BeginOfDay">BeginOfDay</span>

<p>Return begin time of day.</p>

<b>Signature:</b>

```go
func BeginOfDay(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.BeginOfDay(td)
    fmt.Println(bm) //2022-02-15 00:00:00 +0800 CST
}
```

### <span id="BeginOfWeek">BeginOfWeek</span>

<p>Return beginning time of week, week begin from Sunday.</p>

<b>Signature:</b>

```go
func BeginOfWeek(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.BeginOfWeek(td)
    fmt.Println(bm) //2022-02-13 00:00:00 +0800 CST
}
```

### <span id="BeginOfMonth">BeginOfMonth</span>

<p>Return beginning time of month</p>

<b>Signature:</b>

```go
func BeginOfMonth(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.BeginOfMonth(td)
    fmt.Println(bm) //2022-02-01 00:00:00 +0800 CST
}
```

### <span id="BeginOfYear">BeginOfYear</span>

<p>Return beginning time of year.</p>

<b>Signature:</b>

```go
func BeginOfYear(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.BeginOfYear(td)
    fmt.Println(bm) //2022-01-01 00:00:00 +0800 CST
}
```

### <span id="EndOfMinute">EndOfMinute</span>

<p>Return end time minute of day.</p>

<b>Signature:</b>

```go
func EndOfMinute(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.EndOfMinute(td)
    fmt.Println(bm) //2022-02-15 15:48:59.999999999 +0800 CST
}
```

### <span id="EndOfHour">EndOfHour</span>

<p>Return end time hour of day.</p>

<b>Signature:</b>

```go
func EndOfHour(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.EndOfHour(td)
    fmt.Println(bm) //2022-02-15 15:59:59.999999999 +0800 CST
}
```

### <span id="EndOfDay">EndOfDay</span>

<p>Return end time hour of day.</p>

<b>Signature:</b>

```go
func EndOfDay(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.EndOfDay(td)
    fmt.Println(bm) //2022-02-15 23:59:59.999999999 +0800 CST
}
```

### <span id="EndOfWeek">EndOfWeek</span>

<p>Return end time of week, week end with Saturday.</p>

<b>Signature:</b>

```go
func EndOfWeek(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.EndOfWeek(td)
    fmt.Println(bm) //2022-02-19 23:59:59.999999999 +0800 CST
}
```

### <span id="EndOfMonth">EndOfMonth</span>

<p>Return end time of month</p>

<b>Signature:</b>

```go
func EndOfMonth(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.EndOfMonth(td)
    fmt.Println(bm) //2022-02-28 23:59:59.999999999 +0800 CST
}
```

### <span id="EndOfYear">EndOfYear</span>

<p>Return beginning time of year.</p>

<b>Signature:</b>

```go
func EndOfYear(t time.Time) time.Time
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    td := time.Date(2022, 2, 15, 15, 48, 40, 112, time.Local)
    bm := datetime.EndOfYear(td)
    fmt.Println(bm) //2022-12-31 23:59:59.999999999 +0800 CST
}
```

### <span id="GetNowDate">GetNowDate</span>

<p>Get current date string, format is yyyy-mm-dd.</p>

<b>Signature:</b>

```go
func GetNowDate() string
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()
    currentDate := datetime.GetNowDate()
    fmt.Println(currentDate) // 2022-01-28
}
```

### <span id="GetNowTime">GetNowTime</span>

<p>Get current time string, format is hh:mm:ss.</p>

<b>Signature:</b>

```go
func GetNowTime() string
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()
    currentTime := datetime.GetNowTime()
    fmt.Println(currentDate) // 15:57:33
}
```

### <span id="GetNowDateTime">GetNowDateTime</span>

<p>Get current date time string, format is yyyy-mm-dd hh:mm:ss.</p>

<b>Signature:</b>

```go
func GetNowDateTime() string
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()
    current := datetime.GetNowDateTime()
    fmt.Println(current) // 2022-01-28 15:59:33
}
```

### <span id="GetZeroHourTimestamp">GetZeroHourTimestamp</span>

<p>Return timestamp of zero hour (timestamp of 00:00).</p>

<b>Signature:</b>

```go
func GetZeroHourTimestamp() int64
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()
    zeroTime := datetime.GetZeroHourTimestamp()
    fmt.Println(zeroTime) // 1643299200
}
```

### <span id="GetNightTimestamp">GetNightTimestamp</span>

<p>Return timestamp of zero hour (timestamp of 23:59).</p>

<b>Signature:</b>

```go
func GetNightTimestamp() int64
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()
    nightTime := datetime.GetNightTimestamp()
    fmt.Println(nightTime) // 1643385599
}
```

### <span id="FormatTimeToStr">FormatTimeToStr</span>

<p>Format time to string, `format` param specification see note 1.</p>

<b>Signature:</b>

```go
func FormatTimeToStr(t time.Time, format string) string
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "time"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    now := time.Now()
    timeStr := datetime.FormatTimeToStr(now, "yyyy/mm/dd hh:mm:ss")
    fmt.Println(timeStr) //2022/01/28 16:07:44
}
```

### <span id="FormatStrToTime">FormatStrToTime</span>

<p>Format string to time, `format` param specification see note 1.</p>

<b>Signature:</b>

```go
func FormatStrToTime(str, format string) (time.Time, error)
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    time := datetime.FormatStrToTime("2006-01-02 15:04:05", "yyyy/mm/dd hh:mm:ss")
    fmt.Println(time)
}
```

### <span id="NewUnixNow">NewUnixNow</span>

<p>Return unix timestamp of current time</p>

<b>Signature:</b>

```go
type theTime struct {
    unix int64
}
func NewUnixNow() *theTime
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    tm := datetime.NewUnixNow()
    fmt.Println(tm) //&{1647597438}
}
```

### <span id="NewUnix">NewUnix</span>

<p>Return unix timestamp of specified int64 value.</p>

<b>Signature:</b>

```go
type theTime struct {
    unix int64
}
func NewUnix(unix int64) *theTime
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    tm := datetime.NewUnix(1647597438)
    fmt.Println(tm) //&{1647597438}
}
```

### <span id="NewFormat">NewFormat</span>

<p>Return unix timestamp of specified time string, t should be "yyyy-mm-dd hh:mm:ss".</p>

<b>Signature:</b>

```go
type theTime struct {
    unix int64
}
func NewFormat(t string) (*theTime, error)
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    tm, err := datetime.NewFormat("2022-03-18 17:04:05")
    fmt.Println(tm) //&{1647594245}
}
```

### <span id="NewISO8601">NewISO8601</span>

<p>Return unix timestamp of specified iso8601 time string.</p>

<b>Signature:</b>

```go
type theTime struct {
    unix int64
}
func NewISO8601(iso8601 string) (*theTime, error)
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    tm, err := datetime.NewISO8601("2006-01-02T15:04:05.999Z")
    fmt.Println(tm) //&{1136214245}
}
```

### <span id="ToUnix">ToUnix</span>

<p>Return unix timestamp.</p>

<b>Signature:</b>

```go
func (t *theTime) ToUnix() int64
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    tm := datetime.NewUnixNow()
    fmt.Println(tm.ToUnix()) //1647597438
}
```

### <span id="ToFormat">ToFormat</span>

<p>Return time string 'yyyy-mm-dd hh:mm:ss'.</p>

<b>Signature:</b>

```go
func (t *theTime) ToFormat() string
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    tm, _ := datetime.NewFormat("2022-03-18 17:04:05")
    fmt.Println(tm.ToFormat()) //"2022-03-18 17:04:05"
}
```

### <span id="ToFormatForTpl">ToFormatForTpl</span>

<p>Return the time string which format is specified tpl.</p>

<b>Signature:</b>

```go
func (t *theTime) ToFormatForTpl(tpl string) string
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    tm, _ := datetime.NewFormat("2022-03-18 17:04:05")
    ts := tm.ToFormatForTpl("2006/01/02 15:04:05")
    fmt.Println(ts) //"2022/03/18 17:04:05"
}
```

### <span id="ToIso8601">ToIso8601</span>

<p>Return iso8601 time string.</p>

<b>Signature:</b>

```go
func (t *theTime) ToIso8601() string
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    tm, _ := datetime.NewISO8601("2006-01-02T15:04:05.999Z")
    ts := tm.ToIso8601()
    fmt.Println(ts) //"2006-01-02T23:04:05+08:00"
}
```

### <span id="IsLeapYear">IsLeapYear</span>

<p>check if param `year` is leap year or not.</p>

<b>Signature:</b>

```go
func IsLeapYear(year int) bool
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    result1 := datetime.IsLeapYear(2000)
    result2 := datetime.IsLeapYear(2001)

    fmt.Println(result1)
    fmt.Println(result2)

    // Output:
    // true
    // false
}
```

### <span id="BetweenSeconds">BetweenSeconds</span>

<p>Return the number of seconds between two times.</p>

<b>Signature:</b>

```go
func BetweenSeconds(t1 time.Time, t2 time.Time) int64
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    today := time.Now()
    tomorrow := AddDay(today, 1)
    yesterday := AddDay(today, -1)

    result1 := datetime.BetweenSeconds(today, tomorrow)
    result2 := datetime.BetweenSeconds(today, yesterday)

    fmt.Println(result1)
    fmt.Println(result2)

    // Output:
    // 86400
    // -86400
}
```


### <span id="DayOfYear">DayOfYear</span>

<p>Returns which day of the year the parameter date `t` is.</p>

<b>Signature:</b>

```go
func DayOfYear(t time.Time) int
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    date1 := time.Date(2023, 02, 01, 1, 1, 1, 0, time.Local)
    result1 := datetime.DayOfYear(date1)

    date2 := time.Date(2023, 01, 02, 1, 1, 1, 0, time.Local)
    result2 := datetime.DayOfYear(date2)

    date3 := time.Date(2023, 01, 01, 1, 1, 1, 0, time.Local)
    result3 := datetime.DayOfYear(date3)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)

    // Output:
    // 31
    // 1
    // 0
}
```

### <span id="IsWeekend">IsWeekend</span>

<p>Checks if passed time is weekend or not.</p>

<b>Signature:</b>

```go
func IsWeekend(t time.Time) bool
```

<b>Example:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    date1 := time.Date(2023, 06, 03, 0, 0, 0, 0, time.Local)
    date2 := time.Date(2023, 06, 04, 0, 0, 0, 0, time.Local)
    date3 := time.Date(2023, 06, 02, 0, 0, 0, 0, time.Local)

    result1 := datetime.IsWeekend(date1)
    result2 := datetime.IsWeekend(date2)
    result3 := datetime.IsWeekend(date3)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)

    // Output:
    // true
    // true
    // false
}
```

### <span id="IsWeekend">IsWeekend</span>

<p>判断日期是否是周末。</p>

<b>函数签名:</b>

```go
func IsWeekend(t time.Time) bool
```

<b>示例:</b>

```go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/datetime"
)

func main() {
    date1 := time.Date(2023, 06, 03, 0, 0, 0, 0, time.Local)
    date2 := time.Date(2023, 06, 04, 0, 0, 0, 0, time.Local)
    date3 := time.Date(2023, 06, 02, 0, 0, 0, 0, time.Local)

    result1 := datetime.IsWeekend(date1)
    result2 := datetime.IsWeekend(date2)
    result3 := datetime.IsWeekend(date3)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)

    // Output:
    // true
    // true
    // false
}
```