feat: time/timeutil: add Yearquarter, `TimeMore.QuarterCalendar()…

…`, `TimeMore.SeasonMeteorological()`

time/timeutil/constants.go

@@ -19,3 +19,25 @@ const (
 
 	MonthsEN = `["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]`
 )
+
+// A Yearquarter specifies a quarter of the year (Winter = 1, ...).
+type Yearquarter uint8
+
+const (
+	Winter Yearquarter = 1 + iota
+	Spring
+	Summer
+	Autumn
+)
+
+/*
+// String returns the English name of the quarter ("Winter", "Spring", ...).
+func (Yearquarter) String() string {
+	if January <= m && m <= December {
+		return longMonthNames[m-1]
+	}
+	buf := make([]byte, 20)
+	n := fmtInt(buf, uint64(m))
+	return "%!Month(" + string(buf[n:]) + ")"
+}
+*/

time/timeutil/format.go

@@ -154,17 +154,17 @@ func GetFormat(formatName string) (string, error) {
 
 // FormatQuarter takes quarter time and formats it using "Q# YYYY".
 func FormatQuarter(t time.Time) string {
-	return fmt.Sprintf("Q%d %d", MonthToQuarter(uint8(t.Month())), t.Year())
+	return fmt.Sprintf("Q%d %d", MonthToQuarter(t.Month()), t.Year())
 }
 
 // FormatQuarter takes quarter time and formats it using "YYYY Q#".
 func FormatQuarterYYYYQ(t time.Time) string {
-	return fmt.Sprintf("%d Q%d", t.Year(), MonthToQuarter(uint8(t.Month())))
+	return fmt.Sprintf("%d Q%d", t.Year(), MonthToQuarter(t.Month()))
 }
 
 // FormatQuarterYYQ takes quarter time and formats it using "'YY Q#".
 func FormatQuarterYYQ(t time.Time) string {
-	return fmt.Sprintf("%s Q%d", t.Format("'06"), MonthToQuarter(uint8(t.Month())))
+	return fmt.Sprintf("%s Q%d", t.Format("'06"), MonthToQuarter(t.Month()))
 }
 
 func TimeMinRFC3339() time.Time {

time/timeutil/quarter.go

@@ -18,7 +18,7 @@ func QuarterStart(dt time.Time) time.Time {
 
 func QuarterStartString(t time.Time) string {
 	dtStart := NewTimeMore(t, 0).QuarterStart()
-	return fmt.Sprintf("%v Q%v", dtStart.Year(), MonthToQuarter(uint8(dtStart.Month())))
+	return fmt.Sprintf("%v Q%v", dtStart.Year(), MonthToQuarter(dtStart.Month()))
 }
 
 /*
@@ -66,11 +66,15 @@ func quarterPrev(t time.Time, num uint) time.Time {
 }
 
 // MonthToQuarter converts a month to a calendar quarter.
-func MonthToQuarter(month uint8) uint8 {
-	return uint8(math.Ceil(float64(month) / 3))
+func MonthToQuarter(month time.Month) Yearquarter {
+	// func MonthToQuarter(month uint8) uint8 {
+	// return uint8(math.Ceil(float64(month) / 3))
+	return Yearquarter(uint8(math.Ceil(float64(month) / 3)))
 }
 
 // QuarterToMonth converts a calendar quarter to a month.
-func QuarterToMonth(quarter uint8) uint8 {
-	return quarter*3 - 2
+func QuarterToMonth(quarter Yearquarter) time.Month {
+	// func QuarterToMonth(quarter uint8) uint8 {
+	//	return quarter*3 - 2
+	return time.Month(int(quarter)*3 - 2)
 }

time/timeutil/quarter_int.go

@@ -88,7 +88,7 @@ func EqualQuarter(dt1, dt2 time.Time) bool {
 
 func QuarterInt32ForTime(dt time.Time) int32 {
 	dt = dt.UTC()
-	q := MonthToQuarter(uint8(dt.Month()))
+	q := MonthToQuarter(dt.Month())
 	return (int32(dt.Year()) * int32(10)) + int32(q)
 }
 
@@ -135,7 +135,7 @@ func QuarterInt32StartTime(yyyyq int32) (time.Time, error) {
 	if err != nil {
 		return time.Now(), err
 	}
-	qm := QuarterToMonth(q)
+	qm := QuarterToMonth(Yearquarter(q))
 	return time.Date(int(yyyy), time.Month(qm), 1, 0, 0, 0, 0, time.UTC), nil
 }
 
@@ -165,7 +165,7 @@ func QuarterInt32End(yyyyq int32) (time.Time, error) {
 	} else {
 		q += 1
 	}
-	qm := QuarterToMonth(q)
+	qm := QuarterToMonth(Yearquarter(q))
 	return time.Date(int(yyyy), time.Month(qm), 0, 23, 59, 59, 0, time.UTC), nil
 }
 

time/timeutil/quarter_test.go

@@ -47,8 +47,8 @@ var monthToQuarterTests = []struct {
 
 func TestMonthToQuarter(t *testing.T) {
 	for _, tt := range monthToQuarterTests {
-		got := MonthToQuarter(tt.v)
-		if got != tt.want {
+		got := MonthToQuarter(time.Month(tt.v))
+		if got != Yearquarter(tt.want) {
 			t.Errorf("MonthToQuarter(%v): want %v, got %v", tt.v, tt.want, got)
 		}
 	}
@@ -62,8 +62,8 @@ var quarterToMonthTests = []struct {
 
 func TestQuarterToMonth(t *testing.T) {
 	for _, tt := range quarterToMonthTests {
-		got := QuarterToMonth(tt.v)
-		if got != tt.want {
+		got := QuarterToMonth(Yearquarter(tt.v))
+		if got != time.Month(tt.want) {
 			t.Errorf("QuarterToMonth(%v): want %v, got %v", tt.v, tt.want, got)
 		}
 	}

time/timeutil/start_end.go

@@ -27,7 +27,7 @@ func monthStart(dt time.Time) time.Time {
 
 // quarterStart returns a time.Time for the start of the quarter.
 func quarterStart(t time.Time) time.Time {
-	qm := QuarterToMonth(MonthToQuarter(uint8(t.Month())))
+	qm := QuarterToMonth(MonthToQuarter(t.Month()))
 	return time.Date(t.Year(), time.Month(qm), 1, 0, 0, 0, 0, t.Location())
 }
 

time/timeutil/timemore.go

@@ -56,6 +56,35 @@ func (tm TimeMore) IntervalStart(interval Interval) (time.Time, error) {
 	return intervalStart(tm.time, interval, tm.weekStartDay)
 }
 
+// QuarterCalendar returns the quarter of the year specified by tm.Time.
+func (tm TimeMore) QuarterCalendar() Yearquarter {
+	m := tm.time.Month()
+	if m < 4 {
+		return Winter // 1
+	} else if m < 7 {
+		return Spring
+	} else if m < 10 {
+		return Summer
+	} else {
+		return Autumn
+	}
+}
+
+func (tm TimeMore) SeasonMeteorological() Yearquarter {
+	m := tm.time.Month()
+	if m < 3 {
+		return Winter // Starts December 1
+	} else if m < 6 {
+		return Spring // Starts March 1
+	} else if m < 9 {
+		return Summer // Starts June 1
+	} else if m < 12 {
+		return Autumn // Starts September 1
+	} else {
+		return Winter // Starts December 1
+	}
+}
+
 // TimeMeta is a struct for holding various times related
 // to a current time, including year start, quarter start,
 // month start, and week start.