diff --git a/core/expression/src/intellisense/types/provider.rs b/core/expression/src/intellisense/types/provider.rs
index d9861aeb..102625f2 100644
--- a/core/expression/src/intellisense/types/provider.rs
+++ b/core/expression/src/intellisense/types/provider.rs
@@ -237,6 +237,7 @@ impl TypesProvider {
                         | ComparisonOperator::GreaterThan
                         | ComparisonOperator::LessThanOrEqual
                         | ComparisonOperator::GreaterThanOrEqual => match (left_type.deref(), right_type.deref()) {
+                            (VariableType::Date | VariableType::Any, VariableType::Date | VariableType::Any) => V(VariableType::Bool),
                             (VariableType::Number | VariableType::Any, VariableType::Number | VariableType::Any) => V(VariableType::Bool),
                             _ => Error(format!(
                                 "Operator `{operator}` cannot be applied to types `{left_type}` and `{right_type}`."
@@ -257,7 +258,7 @@ impl TypesProvider {
 
                                 V(VariableType::Bool)
                             },
-                            (VariableType::Number, VariableType::Interval) => V(VariableType::Bool),
+                            (VariableType::Number | VariableType::Date, VariableType::Interval) => V(VariableType::Bool),
                             (VariableType::String, VariableType::Object(_)) => V(VariableType::Bool),
                             (VariableType::Any, _) => V(VariableType::Bool),
                             (_, VariableType::Any) => V(VariableType::Bool),
@@ -328,7 +329,9 @@ impl TypesProvider {
             }
             Node::Interval { left, right, .. } => {
                 let left_type = self.determine(left, scope.clone());
-                if !left_type.satisfies(&VariableType::Number) {
+                if !left_type.satisfies(&VariableType::Number)
+                    && !left_type.satisfies(&VariableType::Date)
+                {
                     self.set_error(
                         left,
                         format!("Interval cannot be created from type `{left_type}`."),
@@ -336,7 +339,9 @@ impl TypesProvider {
                 }
 
                 let right_type = self.determine(right, scope.clone());
-                if !right_type.satisfies(&VariableType::Number) {
+                if !right_type.satisfies(&VariableType::Number)
+                    && !right_type.satisfies(&VariableType::Date)
+                {
                     self.set_error(
                         right,
                         format!("Interval cannot be created from type `{right_type}`."),
@@ -352,7 +357,7 @@ impl TypesProvider {
                     .collect();
 
                 if let FunctionKind::Closure(_) = kind {
-                    let ptr_type = type_list[0].array_item().unwrap_or_default();
+                    let ptr_type = type_list[0].iterator().unwrap_or_default();
                     let new_type = self.determine(
                         arguments[1],
                         IntelliSenseScope {
diff --git a/core/expression/src/variable/types/util.rs b/core/expression/src/variable/types/util.rs
index 2c410c26..d48356d5 100644
--- a/core/expression/src/variable/types/util.rs
+++ b/core/expression/src/variable/types/util.rs
@@ -4,9 +4,10 @@ use std::collections::HashMap;
 use std::rc::Rc;
 
 impl VariableType {
-    pub fn array_item(&self) -> Option<Rc<VariableType>> {
+    pub fn iterator(&self) -> Option<Rc<VariableType>> {
         match self {
             VariableType::Array(item) => Some(item.clone()),
+            VariableType::Interval => Some(Rc::new(VariableType::Number)),
             _ => None,
         }
     }
@@ -35,6 +36,8 @@ impl VariableType {
             (VariableType::String, VariableType::String) => true,
             (VariableType::Number, VariableType::Number) => true,
             (VariableType::Date, VariableType::Date) => true,
+            (VariableType::Number, VariableType::Date) => true,
+            (_, VariableType::Date) if self.widen().is_string() => true,
             (VariableType::Interval, VariableType::Interval) => true,
             (VariableType::Array(a1), VariableType::Array(a2)) => a1.satisfies(a2),
             (VariableType::Object(o1), VariableType::Object(o2)) => o1
@@ -71,6 +74,13 @@ impl VariableType {
         }
     }
 
+    pub fn is_string(&self) -> bool {
+        match self {
+            VariableType::String => true,
+            _ => false,
+        }
+    }
+
     pub fn is_object(&self) -> bool {
         match self {
             VariableType::Any | VariableType::Object(_) => true,
diff --git a/core/expression/src/vm/date/mod.rs b/core/expression/src/vm/date/mod.rs
index a77dccb5..e09125ec 100644
--- a/core/expression/src/vm/date/mod.rs
+++ b/core/expression/src/vm/date/mod.rs
@@ -205,7 +205,6 @@ mod helper {
         let tz = tz_opt.unwrap_or_else(|| tz());
 
         match var {
-            Variable::Null => Some(now()),
             Variable::Number(n) => {
                 let n_i64 = n.to_i64()?;
                 let date_time = match tz.timestamp_millis_opt(n_i64) {
diff --git a/core/expression/tests/data/date.csv b/core/expression/tests/data/date.csv
index 99d07bfa..dc879fd8 100644
--- a/core/expression/tests/data/date.csv
+++ b/core/expression/tests/data/date.csv
@@ -111,6 +111,7 @@ d('2023-10-15T14:30:45Z').format('Day %j of year %Y');;'Day 288 of year 2023'
 d('2023-10-15T14:30:45.123Z').format('%H:%M:%S.%f');;'14:30:45.123000000'
 
 # Date validations
+d(null).isValid();;false
 d('foo').isValid();;false
 d('2023-13-01').isValid();;false
 d('2023-02-30').isValid();;false