Merge pull request #387 from moov-io/feat-addbankingtime

feat: AddBankingTime

time.go

@@ -177,3 +177,43 @@ func (t Time) IsWeekend() bool {
 	day := t.Time.Weekday()
 	return day == time.Saturday || day == time.Sunday
 }
+
+// AddBankingTime increments t by the hours, minutes, and seconds provided
+// but keeps the final time within 9am to 5pm in t's Location.
+func (t Time) AddBankingTime(hours, minutes, seconds int) Time {
+	duration := time.Duration(hours) * time.Hour
+	duration += time.Duration(minutes) * time.Minute
+	duration += time.Duration(seconds) * time.Second
+
+	return addBankingDuration(t, duration)
+}
+
+func addBankingDuration(start Time, duration time.Duration) Time {
+	// If we're past the current day's banking hours advance forward one day
+	if start.Hour() >= 17 && (start.Minute() > 0 || start.Second() > 0) {
+		start = start.AddBankingDay(1)
+	}
+
+	// Start the day at 9am or later, but not past 5pm
+	if start.Hour() < 9 || start.Hour() >= 17 {
+		start.Time = time.Date(start.Year(), start.Month(), start.Day(), 9, start.Minute(), start.Second(), 0, start.Location())
+	}
+
+	// Add banking hours as we can
+	for duration > 0 {
+		if start.IsBankingDay() {
+			// Calculate the time remaining in the banking day
+			endOfDay := time.Date(start.Year(), start.Month(), start.Day(), 17, 0, 0, 0, start.Location())
+			remainingToday := endOfDay.Sub(start.Time)
+			if duration < remainingToday {
+				start.Time = start.Time.Add(duration)
+				return start
+			}
+			duration -= remainingToday
+		}
+		// Move to the next banking day starting at 9 AM
+		start = start.AddBankingDay(1)
+		start.Time = time.Date(start.Year(), start.Month(), start.Day(), 9, 0, 0, 0, start.Location())
+	}
+	return start
+}

time_test.go

@@ -505,3 +505,71 @@ func TestTime__YearlyHolidays(t *testing.T) {
 		require.NotEqual(t, cases[i].holiday, NewTime(cases[i].when).IsBankingDay(), description)
 	}
 }
+
+func TestTime_AddBankingTime(t *testing.T) {
+	loc, _ := time.LoadLocation("America/New_York")
+	cases := []struct {
+		input                   time.Time
+		hours, minutes, seconds int
+		expected                time.Time
+	}{
+		{
+			// Normal day -> later that day
+			input: time.Date(2024, time.April, 30, 10, 30, 0, 0, loc),
+			hours: 2, minutes: 25, seconds: 18,
+			expected: time.Date(2024, time.April, 30, 12, 55, 18, 0, loc),
+		},
+		{
+			// Before 9am on banking day, adding less than what gets us to 9am,
+			// should still be +2hrs after 9am
+			input: time.Date(2024, time.April, 30, 2, 30, 0, 0, loc),
+			hours: 2, minutes: 25, seconds: 18,
+			expected: time.Date(2024, time.April, 30, 11, 55, 18, 0, loc),
+		},
+		{
+			// Overlaps to next day
+			input: time.Date(2024, time.April, 30, 10, 30, 0, 0, loc),
+			hours: 7, minutes: 25, seconds: 18,
+			expected: time.Date(2024, time.May, 1, 9, 55, 18, 0, loc),
+		},
+		{
+			// After 5pm on banking day, advanced to next day
+			input: time.Date(2024, time.June, 30, 17, 30, 0, 0, loc),
+			hours: 7, minutes: 25, seconds: 18,
+			expected: time.Date(2024, time.July, 1, 16, 55, 18, 0, loc),
+		},
+		{
+			// After 5pm on bankng day, advance 2+ banking days
+			input: time.Date(2024, time.June, 30, 17, 30, 0, 0, loc),
+			hours: 8, minutes: 25, seconds: 18,
+			expected: time.Date(2024, time.July, 2, 9, 55, 18, 0, loc),
+		},
+		{
+			// Negative, do nothing
+			input: time.Date(2024, time.April, 30, 10, 30, 0, 0, loc),
+			hours: -7, minutes: -25, seconds: -18,
+			expected: time.Date(2024, time.April, 30, 10, 30, 0, 0, loc),
+		},
+		{
+			// Thursday July 4th is a holiday, so move to Friday
+			input: time.Date(2024, time.July, 3, 15, 30, 0, 0, loc),
+			hours: 4, minutes: 12, seconds: 18,
+			expected: time.Date(2024, time.July, 5, 11, 42, 18, 0, loc),
+		},
+		{
+			// Monday May 27th is a holiday, so Thursday -> Tuesday
+			input: time.Date(2024, time.May, 23, 14, 30, 0, 0, loc),
+			hours: 11, minutes: 12, seconds: 18,
+			expected: time.Date(2024, time.May, 28, 9, 42, 18, 0, loc),
+		},
+	}
+	for idx, tc := range cases {
+		t.Run(fmt.Sprintf("case_%d", idx), func(t *testing.T) {
+			desc := fmt.Sprintf("start=%v  hours=%v minutes=%v seconds=%v\n",
+				tc.input.Format(time.RFC3339),
+				tc.hours, tc.minutes, tc.seconds)
+			got := NewTime(tc.input).AddBankingTime(tc.hours, tc.minutes, tc.seconds)
+			require.Equal(t, tc.expected.Format(time.RFC3339), got.Format(time.RFC3339), desc)
+		})
+	}
+}