diff --git a/bindings/python/src/variable.rs b/bindings/python/src/variable.rs
index ffae4536..a12e649e 100644
--- a/bindings/python/src/variable.rs
+++ b/bindings/python/src/variable.rs
@@ -2,7 +2,7 @@ use anyhow::Context;
 use pyo3::prelude::{PyAnyMethods, PyBytesMethods, PyDictMethods, PyListMethods, PyStringMethods};
 use pyo3::types::{PyBytes, PyDict, PyList, PyString};
 use pyo3::{Bound, FromPyObject, IntoPyObject, IntoPyObjectExt, PyAny, PyErr, PyResult, Python};
-use pythonize::depythonize;
+use pythonize::{depythonize, pythonize};
 use rust_decimal::prelude::ToPrimitive;
 use zen_expression::Variable;
 
@@ -40,11 +40,12 @@ pub fn variable_to_object<'py>(py: Python<'py>, val: &Variable) -> PyResult<Boun
             let dict = PyDict::new(py);
             let b = m.borrow();
             for (key, value) in b.iter() {
-                dict.set_item(key, variable_to_object(py, value)?)?;
+                dict.set_item(String::from(key.as_ref()), variable_to_object(py, value)?)?;
             }
 
             dict.into_bound_py_any(py)
         }
+        Variable::Dynamic(d) => Ok(pythonize(py, &d.to_value())?),
     }
 }
 
diff --git a/core/engine/src/handler/function/module/http.rs b/core/engine/src/handler/function/module/http.rs
index b611cdce..7ff49dd8 100644
--- a/core/engine/src/handler/function/module/http.rs
+++ b/core/engine/src/handler/function/module/http.rs
@@ -91,12 +91,13 @@ impl<'js> FromJs<'js> for HttpConfig {
 
                 let value = JsValue::from_js(ctx, value)?;
                 let str_value = match value.0 {
-                    Variable::Null => None,
                     Variable::Bool(b) => Some(b.to_string()),
                     Variable::Number(n) => Some(n.to_string()),
                     Variable::String(s) => Some(s.to_string()),
+                    Variable::Null => None,
                     Variable::Array(_) => None,
                     Variable::Object(_) => None,
+                    Variable::Dynamic(_) => None,
                 };
 
                 let key_value = key.to_string()?;
@@ -121,12 +122,13 @@ impl<'js> FromJs<'js> for HttpConfig {
 
                 let value = JsValue::from_js(ctx, value)?;
                 let str_value = match value.0 {
-                    Variable::Null => None,
                     Variable::Bool(b) => Some(b.to_string()),
                     Variable::Number(n) => Some(n.to_string()),
                     Variable::String(s) => Some(s.to_string()),
+                    Variable::Null => None,
                     Variable::Array(_) => None,
                     Variable::Object(_) => None,
+                    Variable::Dynamic(_) => None,
                 };
 
                 let key = key.to_string()?;
diff --git a/core/engine/src/handler/function/serde.rs b/core/engine/src/handler/function/serde.rs
index 1799167a..97970ba7 100644
--- a/core/engine/src/handler/function/serde.rs
+++ b/core/engine/src/handler/function/serde.rs
@@ -125,6 +125,7 @@ impl<'js> IntoJs<'js> for JsValue {
 
                 qmap.into_value()
             }
+            Variable::Dynamic(d) => d.to_string().into_js(ctx)?,
         };
 
         Ok(res)
diff --git a/core/expression/src/vm/date/mod.rs b/core/expression/src/vm/date/mod.rs
index b0ab5b23..b331d23f 100644
--- a/core/expression/src/vm/date/mod.rs
+++ b/core/expression/src/vm/date/mod.rs
@@ -359,8 +359,8 @@ mod helper {
         };
 
         if let Some(unit_secs) = unit.as_secs() {
-            let secs = (a.timestamp_millis() - b.timestamp_millis()) / 1_000;
-            return secs.checked_mul(unit_secs.to_i64()?);
+            let secs = a.timestamp() - b.timestamp();
+            return secs.checked_div(unit_secs.to_i64()?);
         }
 
         let year_diff = a.year().to_i64()?.checked_sub(b.year().to_i64()?)?;
diff --git a/core/expression/tests/data/date.csv b/core/expression/tests/data/date.csv
new file mode 100644
index 00000000..ed993098
--- /dev/null
+++ b/core/expression/tests/data/date.csv
@@ -0,0 +1,115 @@
+expression (string);input (json 5);output (json 5)
+
+# Date function basics
+d('2023-10-15');;'2023-10-15T00:00:00Z'
+d('2023-10-15 14:30');;'2023-10-15T14:30:00Z'
+d('2023-10-15 14:30:45');;'2023-10-15T14:30:45Z'
+d('2023-10-15', 'Europe/Berlin');;'2023-10-15T00:00:00+02:00'
+d('2023-10-15 14:30', 'Europe/Berlin');;'2023-10-15T14:30:00+02:00'
+d('2023-10-15 14:30:45', 'Europe/Berlin');;'2023-10-15T14:30:45+02:00'
+d('Europe/Berlin').isValid() and d('Europe/Berlin').isToday();;true
+
+# Date manipulation
+d('2023-10-15').add('1d');;'2023-10-16T00:00:00Z'
+d('2023-10-15').add('1d 5h');;'2023-10-16T05:00:00Z'
+d('2023-10-15').add(1, 'd');;'2023-10-16T00:00:00Z'
+d('2023-10-15').sub('2d');;'2023-10-13T00:00:00Z'
+d('2023-10-15').sub(1, 'M');;'2023-09-15T00:00:00Z'
+
+# Date comparisons
+d('2023-10-15').isBefore(d('2023-10-16'));;true
+d('2023-10-15').isBefore(d('2023-10-15'));;false
+d('2023-10-15').isAfter(d('2023-10-14'));;true
+d('2023-10-15').isAfter(d('2023-10-15'));;false
+d('2023-10-15').isSame(d('2023-10-15'));;true
+d('2023-10-15').isSame(d('2023-10-16'));;false
+d('2023-10-15').isSameOrBefore(d('2023-10-15'));;true
+d('2023-10-15').isSameOrBefore(d('2023-10-16'));;true
+d('2023-10-15').isSameOrBefore(d('2023-10-14'));;false
+d('2023-10-15').isSameOrAfter(d('2023-10-15'));;true
+d('2023-10-15').isSameOrAfter(d('2023-10-14'));;true
+d('2023-10-15').isSameOrAfter(d('2023-10-16'));;false
+
+# Date getters
+d('2023-10-15').year();;2023
+d('2023-10-15').month();;10
+d('2023-10-15').day();;15
+d('2023-10-15').weekday();;0
+d('2023-10-15').hour();;0
+d('2023-10-15').minute();;0
+d('2023-10-15').second();;0
+d('2023-10-15').dayOfYear();;288
+d('2023-01-01').dayOfYear();;1
+d('2023-12-31').dayOfYear();;365
+d('2024-12-31').dayOfYear();;366
+d('2023-10-15').quarter();;4
+d('2023-01-15').quarter();;1
+d('2023-04-15').quarter();;2
+d('2023-07-15').quarter();;3
+d('2023-10-15').timestamp();;1697328000000
+d('2023-10-15', 'Europe/Berlin').offsetName();;'Europe/Berlin'
+d('2023-10-15', 'America/Los_Angeles').offsetName();;'America/Los_Angeles'
+d('2023-10-15').isLeapYear();;false
+d('2024-10-15').isLeapYear();;true
+d('2000-10-15').isLeapYear();;true
+d('1900-10-15').isLeapYear();;false
+
+# Date setters
+d('2023-10-15').set(2024, 'year');;'2024-10-15T00:00:00Z'
+d('2023-10-15').set(5, 'month');;'2023-05-15T00:00:00Z'
+d('2023-10-15').set(20, 'day');;'2023-10-20T00:00:00Z'
+d('2023-10-15T10:30:00Z').set(15, 'hour');;'2023-10-15T15:30:00Z'
+d('2023-10-15T10:30:00Z').set(45, 'minute');;'2023-10-15T10:45:00Z'
+d('2023-10-15T10:30:00Z').set(30, 'second');;'2023-10-15T10:30:30Z'
+
+# Special date checks
+d().isSame(d(), 'day');;true
+d('2023-10-15').startOf('day');;'2023-10-15T00:00:00Z'
+d('2023-10-15T10:30:45Z').startOf('hour');;'2023-10-15T10:00:00Z'
+d('2023-10-15').endOf('day');;'2023-10-15T23:59:59Z'
+d('2023-10-15T10:30:45Z').endOf('hour');;'2023-10-15T10:59:59Z'
+d('2023-10-15').startOf('month');;'2023-10-01T00:00:00Z'
+d('2023-10-15').endOf('month');;'2023-10-31T23:59:59Z'
+d('2023-10-15').startOf('year');;'2023-01-01T00:00:00Z'
+d('2023-10-15').endOf('year');;'2023-12-31T23:59:59Z'
+d('2023-10-15').startOf('week');;'2023-10-09T00:00:00Z'
+d('2023-10-15').endOf('week');;'2023-10-15T23:59:59Z'
+d('2023-10-15').startOf('quarter');;'2023-10-01T00:00:00Z'
+d('2023-10-15').endOf('quarter');;'2023-12-31T23:59:59Z'
+d('2023-03-15').startOf('quarter');;'2023-01-01T00:00:00Z'
+d('2023-03-15').endOf('quarter');;'2023-03-31T23:59:59Z'
+d('2023-06-15').startOf('quarter');;'2023-04-01T00:00:00Z'
+d('2023-06-15').endOf('quarter');;'2023-06-30T23:59:59Z'
+d('2023-09-15').startOf('quarter');;'2023-07-01T00:00:00Z'
+d('2023-09-15').endOf('quarter');;'2023-09-30T23:59:59Z'
+
+# Timezone operations
+d('2023-10-15T00:00:00Z').tz('America/New_York');;'2023-10-14T20:00:00-04:00'
+d('2023-10-15T00:00:00Z').tz('Europe/London');;'2023-10-15T01:00:00+01:00'
+d('2023-10-15T00:00:00+00:00').tz('UTC');;'2023-10-15T00:00:00Z'
+d('2023-10-15T12:00:00+02:00', 'Etc/GMT-2').tz('UTC');;'2023-10-15T10:00:00Z'
+
+# Relative date methods
+d().sub(1, 'd').isYesterday();;true
+d().add(1, 'd').isTomorrow();;true
+d('2023-10-15').isToday();;false
+
+# Difference calculations
+d('2023-10-15').diff(d('2023-10-10'), 'day');;5
+d('2023-10-15T10:00:00Z').diff(d('2023-10-15T08:30:00Z'), 'hour');;1
+d('2023-10-15').diff(d('2023-09-15'), 'month');;1
+d('2023-12-31').diff(d('2023-01-01'), 'year');;0
+d('2023-12-31').diff(d('2022-01-01'), 'year');;1
+
+# Formatting
+d('2023-10-15').format('%Y-%m-%d');;'2023-10-15'
+d('2023-10-15').format('%Y/%m/%d');;'2023/10/15'
+d('2023-10-15T14:30:45Z').format('%A, %B %d %Y, %H:%M:%S');;'Sunday, October 15 2023, 14:30:45'
+d('2023-10-15T14:30:45Z').format('%a %b %d %H:%M');;'Sun Oct 15 14:30'
+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('foo').isValid();;false
+d('2023-13-01').isValid();;false
+d('2023-02-30').isValid();;false
\ No newline at end of file
diff --git a/core/expression/tests/isolate.rs b/core/expression/tests/isolate.rs
index 5299ae7c..82a029e8 100644
--- a/core/expression/tests/isolate.rs
+++ b/core/expression/tests/isolate.rs
@@ -1,6 +1,3 @@
-use std::ops::Index;
-
-use anyhow::Context;
 use serde_json::{json, Value};
 
 use zen_expression::variable::Variable;
@@ -754,86 +751,106 @@ fn isolate_unary_tests() {
     }
 }
 
-#[test]
-fn isolate_test_decimals() {
-    let mut isolate = Isolate::new();
-    let result = isolate.run_standard("9223372036854775807").unwrap();
+#[cfg(test)]
+mod test {
+    use anyhow::Context;
+    use serde_json::Value;
+    use std::env;
+    use std::ops::Index;
+    use zen_expression::Isolate;
 
-    assert_eq!(result.to_value(), Value::from(9223372036854775807i64));
-}
+    fn test_csv_standard(csv_data: &str) {
+        let mut r = csv::ReaderBuilder::new()
+            .delimiter(b';')
+            .from_reader(csv_data.as_bytes());
 
-#[test]
-fn test_standard_csv() {
-    let csv_data = include_str!("data/standard.csv");
-    let mut r = csv::ReaderBuilder::new()
-        .delimiter(b';')
-        .from_reader(csv_data.as_bytes());
+        while let Some(maybe_row) = r.records().next() {
+            let Ok(row) = maybe_row else {
+                continue;
+            };
 
-    while let Some(maybe_row) = r.records().next() {
-        let Ok(row) = maybe_row else {
-            continue;
-        };
+            let (expression, input_str, output_str) = (row.index(0), row.index(1), row.index(2));
+            if expression.starts_with("#") {
+                continue;
+            }
 
-        let (expression, input_str, output_str) = (row.index(0), row.index(1), row.index(2));
-        if expression.starts_with("#") {
-            continue;
+            let output: Value = serde_json5::from_str(output_str).unwrap();
+
+            let mut isolate = Isolate::new();
+            if !input_str.is_empty() {
+                let input: Value = serde_json5::from_str(input_str).unwrap();
+                isolate.set_environment(input.into());
+            }
+
+            let maybe_result = isolate
+                .run_standard(expression)
+                .context(format!("Expression: {expression}"));
+            assert!(maybe_result.is_ok(), "{}", maybe_result.unwrap_err());
+
+            let result = maybe_result.unwrap().to_value();
+            assert_eq!(
+                result, output,
+                "Expression {expression}. Expected: {output}, got: {result}"
+            );
         }
+    }
 
-        let output: Value = serde_json5::from_str(output_str).unwrap();
-
+    #[test]
+    fn isolate_test_decimals() {
         let mut isolate = Isolate::new();
-        if !input_str.is_empty() {
-            let input: Value = serde_json5::from_str(input_str).unwrap();
-            isolate.set_environment(input.into());
+        let result = isolate.run_standard("9223372036854775807").unwrap();
+
+        assert_eq!(result.to_value(), Value::from(9223372036854775807i64));
+    }
+
+    #[test]
+    fn test_standard_csv() {
+        let csv_data = include_str!("data/standard.csv");
+        test_csv_standard(csv_data);
+    }
+
+    #[test]
+    fn test_dates_csv() {
+        env::set_var("TZ", "UTC");
+
+        let csv_data = include_str!("data/date.csv");
+        test_csv_standard(csv_data);
+    }
+
+    #[test]
+    fn test_unary_csv() {
+        let csv_data = include_str!("data/unary.csv");
+        let mut r = csv::ReaderBuilder::new()
+            .delimiter(b';')
+            .from_reader(csv_data.as_bytes());
+
+        while let Some(maybe_row) = r.records().next() {
+            let Ok(row) = maybe_row else {
+                continue;
+            };
+
+            let (expression, input_str, output_str) = (row.index(0), row.index(1), row.index(2));
+            if expression.starts_with("#") {
+                continue;
+            }
+
+            let output: Value = serde_json5::from_str(output_str).unwrap();
+
+            let mut isolate = Isolate::new();
+            if !input_str.is_empty() {
+                let input: Value = serde_json5::from_str(input_str).unwrap();
+                isolate.set_environment(input.into());
+            }
+
+            let result = isolate
+                .run_unary(expression)
+                .context(format!("Expression: {expression}"))
+                .unwrap();
+
+            assert_eq!(
+                result, output,
+                "Expression {expression}. Expected: {output}, got: {result}"
+            );
         }
-
-        let maybe_result = isolate
-            .run_standard(expression)
-            .context(format!("Expression: {expression}"));
-        assert!(maybe_result.is_ok(), "{}", maybe_result.unwrap_err());
-
-        let result = maybe_result.unwrap();
-        let var_output = Variable::from(output);
-        assert_eq!(
-            result, var_output,
-            "Expression {expression}. Expected: {var_output}, got: {result}"
-        );
-    }
-}
-
-#[test]
-fn test_unary_csv() {
-    let csv_data = include_str!("data/unary.csv");
-    let mut r = csv::ReaderBuilder::new()
-        .delimiter(b';')
-        .from_reader(csv_data.as_bytes());
-
-    while let Some(maybe_row) = r.records().next() {
-        let Ok(row) = maybe_row else {
-            continue;
-        };
-
-        let (expression, input_str, output_str) = (row.index(0), row.index(1), row.index(2));
-        if expression.starts_with("#") {
-            continue;
-        }
-
-        let output: Value = serde_json5::from_str(output_str).unwrap();
-
-        let mut isolate = Isolate::new();
-        if !input_str.is_empty() {
-            let input: Value = serde_json5::from_str(input_str).unwrap();
-            isolate.set_environment(input.into());
-        }
-
-        let result = isolate
-            .run_unary(expression)
-            .context(format!("Expression: {expression}"))
-            .unwrap();
-
-        assert_eq!(
-            result, output,
-            "Expression {expression}. Expected: {output}, got: {result}"
-        );
     }
 }