diff --git a/pkg/stdlib/datetime/date_test.go b/pkg/stdlib/datetime/date_test.go
index 221fcbb3..ab4298e3 100644
--- a/pkg/stdlib/datetime/date_test.go
+++ b/pkg/stdlib/datetime/date_test.go
@@ -26,6 +26,12 @@ func TestDate(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When incorrect timeStrings",
 			Expected: values.None,
diff --git a/pkg/stdlib/datetime/day_test.go b/pkg/stdlib/datetime/day_test.go
index bb7ded3d..192ad8c0 100644
--- a/pkg/stdlib/datetime/day_test.go
+++ b/pkg/stdlib/datetime/day_test.go
@@ -25,6 +25,12 @@ func TestDateDay(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When 7th day",
 			Expected: values.NewInt(7),
diff --git a/pkg/stdlib/datetime/dayofweek_test.go b/pkg/stdlib/datetime/dayofweek_test.go
index 617cfef6..dcef7588 100644
--- a/pkg/stdlib/datetime/dayofweek_test.go
+++ b/pkg/stdlib/datetime/dayofweek_test.go
@@ -25,6 +25,12 @@ func TestDateDayOfWeek(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When Sunday (0th day)",
 			Expected: values.NewInt(0),
diff --git a/pkg/stdlib/datetime/dayofyear_test.go b/pkg/stdlib/datetime/dayofyear_test.go
index a847befb..50c16f3f 100644
--- a/pkg/stdlib/datetime/dayofyear_test.go
+++ b/pkg/stdlib/datetime/dayofyear_test.go
@@ -26,6 +26,12 @@ func TestDateDayOfYear(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When 38th day of the year",
 			Expected: values.NewInt(38),
diff --git a/pkg/stdlib/datetime/daysinmonth_test.go b/pkg/stdlib/datetime/daysinmonth_test.go
index 8b05a3d1..ac5ab7d2 100644
--- a/pkg/stdlib/datetime/daysinmonth_test.go
+++ b/pkg/stdlib/datetime/daysinmonth_test.go
@@ -26,6 +26,12 @@ func TestDateDateDaysInMonth(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When Feb and a leap year",
 			Expected: values.NewInt(29),
diff --git a/pkg/stdlib/datetime/hour_test.go b/pkg/stdlib/datetime/hour_test.go
index 1118c1ea..f1206415 100644
--- a/pkg/stdlib/datetime/hour_test.go
+++ b/pkg/stdlib/datetime/hour_test.go
@@ -25,6 +25,12 @@ func TestDateHour(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When 7th hour",
 			Expected: values.NewInt(7),
diff --git a/pkg/stdlib/datetime/leapyear_test.go b/pkg/stdlib/datetime/leapyear_test.go
index d25f2984..5ffaea54 100644
--- a/pkg/stdlib/datetime/leapyear_test.go
+++ b/pkg/stdlib/datetime/leapyear_test.go
@@ -25,6 +25,12 @@ func TestDateLeapYear(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When not a leap year",
 			Expected: values.NewBoolean(false),
diff --git a/pkg/stdlib/datetime/millisecond_test.go b/pkg/stdlib/datetime/millisecond_test.go
index b8d42bf4..02ee66c0 100644
--- a/pkg/stdlib/datetime/millisecond_test.go
+++ b/pkg/stdlib/datetime/millisecond_test.go
@@ -26,6 +26,12 @@ func TestDateMillisecond(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When 129 millisecond",
 			Expected: values.NewInt(129),
diff --git a/pkg/stdlib/datetime/minute_test.go b/pkg/stdlib/datetime/minute_test.go
index f2fbbffd..46a6eff3 100644
--- a/pkg/stdlib/datetime/minute_test.go
+++ b/pkg/stdlib/datetime/minute_test.go
@@ -25,6 +25,12 @@ func TestDateMinute(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When 4th minute",
 			Expected: values.NewInt(4),
diff --git a/pkg/stdlib/datetime/month_test.go b/pkg/stdlib/datetime/month_test.go
index 56927880..c49e138e 100644
--- a/pkg/stdlib/datetime/month_test.go
+++ b/pkg/stdlib/datetime/month_test.go
@@ -25,6 +25,12 @@ func TestDateMonth(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When 2th month",
 			Expected: values.NewInt(2),
diff --git a/pkg/stdlib/datetime/quarter_test.go b/pkg/stdlib/datetime/quarter_test.go
index 3b29c7f2..96aca870 100644
--- a/pkg/stdlib/datetime/quarter_test.go
+++ b/pkg/stdlib/datetime/quarter_test.go
@@ -26,6 +26,12 @@ func TestDateQuarter(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 	}
 
 	for month := time.January; month <= time.December; month++ {
diff --git a/pkg/stdlib/datetime/second_test.go b/pkg/stdlib/datetime/second_test.go
index 64f194b4..c7e596c8 100644
--- a/pkg/stdlib/datetime/second_test.go
+++ b/pkg/stdlib/datetime/second_test.go
@@ -25,6 +25,12 @@ func TestDateSecond(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When 5th second",
 			Expected: values.NewInt(5),
diff --git a/pkg/stdlib/datetime/year_test.go b/pkg/stdlib/datetime/year_test.go
index 29b9ab0b..fbddcaa9 100644
--- a/pkg/stdlib/datetime/year_test.go
+++ b/pkg/stdlib/datetime/year_test.go
@@ -25,6 +25,12 @@ func TestDateYear(t *testing.T) {
 			Args:      []core.Value{},
 			ShouldErr: true,
 		},
+		&testCase{
+			Name:      "When argument isn't DateTime",
+			Expected:  values.None,
+			Args:      []core.Value{values.NewInt(0)},
+			ShouldErr: true,
+		},
 		&testCase{
 			Name:     "When 1999th year",
 			Expected: values.NewInt(1999),