test&doc: add example and update doc for datetime package

datetime/datetime.go

@@ -54,54 +54,64 @@ func init() {
 	}
 }
 
-// AddMinute add or sub minute to the time
+// AddMinute add or sub minute to the time.
+// Play: https://go.dev/play/p/nT1heB1KUUK
 func AddMinute(t time.Time, minute int64) time.Time {
 	return t.Add(time.Minute * time.Duration(minute))
 }
 
-// AddHour add or sub hour to the time
+// AddHour add or sub hour to the time.
+// Play: https://go.dev/play/p/rcMjd7OCsi5
 func AddHour(t time.Time, hour int64) time.Time {
 	return t.Add(time.Hour * time.Duration(hour))
 }
 
-// AddDay add or sub day to the time
+// AddDay add or sub day to the time.
+// Play: https://go.dev/play/p/dIGbs_uTdFa
 func AddDay(t time.Time, day int64) time.Time {
 	return t.Add(24 * time.Hour * time.Duration(day))
 }
 
-// GetNowDate return format yyyy-mm-dd of current date
+// GetNowDate return format yyyy-mm-dd of current date.
+// Play: https://go.dev/play/p/PvfkPpcpBBf
 func GetNowDate() string {
 	return time.Now().Format("2006-01-02")
 }
 
-// GetNowTime return format hh-mm-ss of current time
+// GetNowTime return format hh-mm-ss of current time.
+// Play: https://go.dev/play/p/l7BNxCkTmJS
 func GetNowTime() string {
 	return time.Now().Format("15:04:05")
 }
 
-// GetNowDateTime return format yyyy-mm-dd hh-mm-ss of current datetime
+// GetNowDateTime return format yyyy-mm-dd hh-mm-ss of current datetime.
+// Play: https://go.dev/play/p/pI4AqngD0al
 func GetNowDateTime() string {
 	return time.Now().Format("2006-01-02 15:04:05")
 }
 
-// GetZeroHourTimestamp return timestamp of zero hour (timestamp of 00:00)
+// GetZeroHourTimestamp return timestamp of zero hour (timestamp of 00:00).
+// Play: https://go.dev/play/p/QmL2oIaGE3q
 func GetZeroHourTimestamp() int64 {
 	ts := time.Now().Format("2006-01-02")
 	t, _ := time.Parse("2006-01-02", ts)
 	return t.UTC().Unix() - 8*3600
 }
 
-// GetNightTimestamp return timestamp of zero hour (timestamp of 23:59)
+// GetNightTimestamp return timestamp of zero hour (timestamp of 23:59).
+// Play: https://go.dev/play/p/UolysR3MYP1
 func GetNightTimestamp() int64 {
 	return GetZeroHourTimestamp() + 86400 - 1
 }
 
-// FormatTimeToStr convert time to string
+// FormatTimeToStr convert time to string.
+// Play: https://go.dev/play/p/_Ia7M8H_OvE
 func FormatTimeToStr(t time.Time, format string) string {
 	return t.Format(timeFormat[format])
 }
 
-// FormatStrToTime convert string to time
+// FormatStrToTime convert string to time.
+// Play: https://go.dev/play/p/1h9FwdU8ql4
 func FormatStrToTime(str, format string) (time.Time, error) {
 	v, ok := timeFormat[format]
 	if !ok {
@@ -111,43 +121,50 @@ func FormatStrToTime(str, format string) (time.Time, error) {
 	return time.Parse(v, str)
 }
 
-// BeginOfMinute return beginning minute time of day
+// BeginOfMinute return beginning minute time of day.
+// Play: https://go.dev/play/p/ieOLVJ9CiFT
 func BeginOfMinute(t time.Time) time.Time {
 	y, m, d := t.Date()
 	return time.Date(y, m, d, t.Hour(), t.Minute(), 0, 0, t.Location())
 }
 
-// EndOfMinute return end minute time of day
+// EndOfMinute return end minute time of day.
+// Play: https://go.dev/play/p/yrL5wGzPj4z
 func EndOfMinute(t time.Time) time.Time {
 	y, m, d := t.Date()
 	return time.Date(y, m, d, t.Hour(), t.Minute(), 59, int(time.Second-time.Nanosecond), t.Location())
 }
 
-// BeginOfHour return beginning hour time of day
+// BeginOfHour return beginning hour time of day.
+// Play: https://go.dev/play/p/GhdGFnDWpYs
 func BeginOfHour(t time.Time) time.Time {
 	y, m, d := t.Date()
 	return time.Date(y, m, d, t.Hour(), 0, 0, 0, t.Location())
 }
 
-// EndOfHour return end hour time of day
+// EndOfHour return end hour time of day.
+// Play: https://go.dev/play/p/6ce3j_6cVqN
 func EndOfHour(t time.Time) time.Time {
 	y, m, d := t.Date()
 	return time.Date(y, m, d, t.Hour(), 59, 59, int(time.Second-time.Nanosecond), t.Location())
 }
 
-// BeginOfDay return beginning hour time of day
+// BeginOfDay return beginning hour time of day.
+// Play: https://go.dev/play/p/94m_UT6cWs9
 func BeginOfDay(t time.Time) time.Time {
 	y, m, d := t.Date()
 	return time.Date(y, m, d, 0, 0, 0, 0, t.Location())
 }
 
-// EndOfDay return end time of day
+// EndOfDay return end time of day.
+// Play: https://go.dev/play/p/eMBOvmq5Ih1
 func EndOfDay(t time.Time) time.Time {
 	y, m, d := t.Date()
 	return time.Date(y, m, d, 23, 59, 59, int(time.Second-time.Nanosecond), t.Location())
 }
 
-// BeginOfWeek return beginning week, default week begin from Sunday
+// BeginOfWeek return beginning week, default week begin from Sunday.
+// Play: https://go.dev/play/p/ynjoJPz7VNV
 func BeginOfWeek(t time.Time, beginFrom ...time.Weekday) time.Time {
 	var beginFromWeekday = time.Sunday
 	if len(beginFrom) > 0 {
@@ -161,7 +178,8 @@ func BeginOfWeek(t time.Time, beginFrom ...time.Weekday) time.Time {
 	return beginOfWeek
 }
 
-// EndOfWeek return end week time, default week end with Saturday
+// EndOfWeek return end week time, default week end with Saturday.
+// Play: https://go.dev/play/p/i08qKXD9flf
 func EndOfWeek(t time.Time, endWith ...time.Weekday) time.Time {
 	var endWithWeekday = time.Saturday
 	if len(endWith) > 0 {
@@ -175,24 +193,28 @@ func EndOfWeek(t time.Time, endWith ...time.Weekday) time.Time {
 	return endWithWeek
 }
 
-// BeginOfMonth return beginning of month
+// BeginOfMonth return beginning of month.
+// Play: https://go.dev/play/p/bWXVFsmmzwL
 func BeginOfMonth(t time.Time) time.Time {
 	y, m, _ := t.Date()
 	return time.Date(y, m, 1, 0, 0, 0, 0, t.Location())
 }
 
-// EndOfMonth return end of month
+// EndOfMonth return end of month.
+// Play: https://go.dev/play/p/_GWh10B3Nqi
 func EndOfMonth(t time.Time) time.Time {
 	return BeginOfMonth(t).AddDate(0, 1, 0).Add(-time.Nanosecond)
 }
 
-// BeginOfYear return beginning of year
+// BeginOfYear return the date time at the begin of year.
+// Play: https://go.dev/play/p/i326DSwLnV8
 func BeginOfYear(t time.Time) time.Time {
 	y, _, _ := t.Date()
 	return time.Date(y, time.January, 1, 0, 0, 0, 0, t.Location())
 }
 
-// EndOfYear return end of year
+// EndOfYear return the date time at the end of year.
+// Play: https://go.dev/play/p/G01cKlMCvNm
 func EndOfYear(t time.Time) time.Time {
 	return BeginOfYear(t).AddDate(1, 0, 0).Add(-time.Nanosecond)
 }