feat: add DaysBetween in datetime package

datetime/datetime.go

@@ -411,3 +411,12 @@ func getCallerName() string {
 
 	return fullName
 }
+
+// DaysBetween returns the number of days between two times.
+// Play: todo
+func DaysBetween(start, end time.Time) int {
+	duration := end.Sub(start)
+	days := int(duration.Hours() / 24)
+
+	return days
+}

datetime/datetime_example_test.go

@@ -409,16 +409,14 @@ func ExampleIsWeekend() {
 	// false
 }
 
-// func ExampleTrackFuncTime() {
-// 	defer TrackFuncTime(time.Now())()
+func ExampleDaysBetween() {
+	start := time.Date(2024, time.September, 1, 0, 0, 0, 0, time.UTC)
+	end := time.Date(2024, time.September, 10, 0, 0, 0, 0, time.UTC)
 
-// 	var n int
-// 	for i := 0; i < 5000000; i++ {
-// 		n++
-// 	}
+	result := DaysBetween(start, end)
 
-// 	fmt.Println(1)
+	fmt.Println(result)
 
-// 	// Output:
-// 	// 1
-// }
+	// Output:
+	// 9
+}

datetime/datetime_test.go

@@ -419,3 +419,46 @@ func TestTrackFuncTime(t *testing.T) {
 		n++
 	}
 }
+
+func TestDaysBetween(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestDaysBetween")
+
+	tests := []struct {
+		start    time.Time
+		end      time.Time
+		expected int
+	}{
+		{
+			start:    time.Date(2024, time.September, 1, 0, 0, 0, 0, time.UTC),
+			end:      time.Date(2024, time.September, 10, 0, 0, 0, 0, time.UTC),
+			expected: 9,
+		},
+		{
+			start:    time.Date(2024, time.September, 10, 0, 0, 0, 0, time.UTC),
+			end:      time.Date(2024, time.September, 1, 0, 0, 0, 0, time.UTC),
+			expected: -9,
+		},
+		{
+			start:    time.Date(2024, time.September, 1, 0, 0, 0, 0, time.UTC),
+			end:      time.Date(2024, time.September, 1, 0, 0, 0, 0, time.UTC),
+			expected: 0,
+		},
+		{
+			start:    time.Date(2024, time.January, 1, 0, 0, 0, 0, time.UTC),
+			end:      time.Date(2024, time.December, 31, 0, 0, 0, 0, time.UTC),
+			expected: 365,
+		},
+		{
+			start:    time.Date(2024, time.March, 1, 0, 0, 0, 0, time.UTC),
+			end:      time.Date(2024, time.March, 31, 0, 0, 0, 0, time.UTC),
+			expected: 30,
+		},
+	}
+
+	for _, tt := range tests {
+		result := DaysBetween(tt.start, tt.end)
+		assert.Equal(tt.expected, result)
+	}
+}