diff --git a/datafusion/core/src/execution/session_state_defaults.rs b/datafusion/core/src/execution/session_state_defaults.rs
index a241738bd3a4..baf396f3f1c5 100644
--- a/datafusion/core/src/execution/session_state_defaults.rs
+++ b/datafusion/core/src/execution/session_state_defaults.rs
@@ -90,11 +90,10 @@ impl SessionStateDefaults {
             Arc::new(functions_nested::planner::NestedFunctionPlanner),
             #[cfg(feature = "nested_expressions")]
             Arc::new(functions_nested::planner::FieldAccessPlanner),
-            #[cfg(any(
-                feature = "datetime_expressions",
-                feature = "unicode_expressions"
-            ))]
-            Arc::new(functions::planner::UserDefinedFunctionPlanner),
+            #[cfg(feature = "datetime_expressions")]
+            Arc::new(functions::datetime::planner::DatetimeFunctionPlanner),
+            #[cfg(feature = "unicode_expressions")]
+            Arc::new(functions::unicode::planner::UnicodeFunctionPlanner),
             Arc::new(functions_aggregate::planner::AggregateFunctionPlanner),
             Arc::new(functions_window::planner::WindowFunctionPlanner),
         ];
diff --git a/datafusion/functions/src/datetime/mod.rs b/datafusion/functions/src/datetime/mod.rs
index dee40215c9ea..5729b1edae95 100644
--- a/datafusion/functions/src/datetime/mod.rs
+++ b/datafusion/functions/src/datetime/mod.rs
@@ -30,6 +30,7 @@ pub mod date_trunc;
 pub mod from_unixtime;
 pub mod make_date;
 pub mod now;
+pub mod planner;
 pub mod to_char;
 pub mod to_date;
 pub mod to_local_time;
diff --git a/datafusion/functions/src/datetime/planner.rs b/datafusion/functions/src/datetime/planner.rs
new file mode 100644
index 000000000000..f4b64c3711e2
--- /dev/null
+++ b/datafusion/functions/src/datetime/planner.rs
@@ -0,0 +1,35 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+//! SQL planning extensions like [`DatetimeFunctionPlanner`]
+use datafusion_expr::expr::ScalarFunction;
+use datafusion_expr::planner::{ExprPlanner, PlannerResult};
+use datafusion_expr::Expr;
+
+#[derive(Default, Debug)]
+pub struct DatetimeFunctionPlanner;
+
+impl ExprPlanner for DatetimeFunctionPlanner {
+    fn plan_extract(
+        &self,
+        args: Vec<Expr>,
+    ) -> datafusion_common::Result<PlannerResult<Vec<Expr>>> {
+        Ok(PlannerResult::Planned(Expr::ScalarFunction(
+            ScalarFunction::new_udf(crate::datetime::date_part(), args),
+        )))
+    }
+}
diff --git a/datafusion/functions/src/planner.rs b/datafusion/functions/src/planner.rs
index 93edec7ece30..7228cdc07e72 100644
--- a/datafusion/functions/src/planner.rs
+++ b/datafusion/functions/src/planner.rs
@@ -24,9 +24,14 @@ use datafusion_expr::{
     Expr,
 };
 
+#[deprecated(
+    since = "0.50.0",
+    note = "Use UnicodeFunctionPlanner and DateTimeFunctionPlanner instead"
+)]
 #[derive(Default, Debug)]
 pub struct UserDefinedFunctionPlanner;
 
+#[expect(deprecated)]
 impl ExprPlanner for UserDefinedFunctionPlanner {
     #[cfg(feature = "datetime_expressions")]
     fn plan_extract(&self, args: Vec<Expr>) -> Result<PlannerResult<Vec<Expr>>> {
diff --git a/datafusion/functions/src/unicode/mod.rs b/datafusion/functions/src/unicode/mod.rs
index 3c5cde3789ea..4a0dd21d749a 100644
--- a/datafusion/functions/src/unicode/mod.rs
+++ b/datafusion/functions/src/unicode/mod.rs
@@ -26,6 +26,7 @@ pub mod find_in_set;
 pub mod initcap;
 pub mod left;
 pub mod lpad;
+pub mod planner;
 pub mod reverse;
 pub mod right;
 pub mod rpad;
diff --git a/datafusion/functions/src/unicode/planner.rs b/datafusion/functions/src/unicode/planner.rs
new file mode 100644
index 000000000000..e4f29be3d13d
--- /dev/null
+++ b/datafusion/functions/src/unicode/planner.rs
@@ -0,0 +1,45 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+//! SQL planning extensions like [`UnicodeFunctionPlanner`]
+
+use datafusion_expr::expr::ScalarFunction;
+use datafusion_expr::planner::{ExprPlanner, PlannerResult};
+use datafusion_expr::Expr;
+
+#[derive(Default, Debug)]
+pub struct UnicodeFunctionPlanner;
+
+impl ExprPlanner for UnicodeFunctionPlanner {
+    fn plan_position(
+        &self,
+        args: Vec<Expr>,
+    ) -> datafusion_common::Result<PlannerResult<Vec<Expr>>> {
+        Ok(PlannerResult::Planned(Expr::ScalarFunction(
+            ScalarFunction::new_udf(crate::unicode::strpos(), args),
+        )))
+    }
+
+    fn plan_substring(
+        &self,
+        args: Vec<Expr>,
+    ) -> datafusion_common::Result<PlannerResult<Vec<Expr>>> {
+        Ok(PlannerResult::Planned(Expr::ScalarFunction(
+            ScalarFunction::new_udf(crate::unicode::substr(), args),
+        )))
+    }
+}
diff --git a/datafusion/sql/tests/cases/plan_to_sql.rs b/datafusion/sql/tests/cases/plan_to_sql.rs
index cffb062974e5..a35836420c6e 100644
--- a/datafusion/sql/tests/cases/plan_to_sql.rs
+++ b/datafusion/sql/tests/cases/plan_to_sql.rs
@@ -51,7 +51,7 @@ use datafusion_expr::builder::{
     project, subquery_alias, table_scan_with_filter_and_fetch, table_scan_with_filters,
 };
 use datafusion_functions::core::planner::CoreFunctionPlanner;
-use datafusion_functions::planner::UserDefinedFunctionPlanner;
+use datafusion_functions::unicode::planner::UnicodeFunctionPlanner;
 use datafusion_functions_nested::extract::array_element_udf;
 use datafusion_functions_nested::planner::{FieldAccessPlanner, NestedFunctionPlanner};
 use datafusion_sql::unparser::ast::{
@@ -1341,7 +1341,7 @@ where
             .with_scalar_function(Arc::new(unicode::substr().as_ref().clone()))
             .with_scalar_function(make_array_udf())
             .with_expr_planner(Arc::new(CoreFunctionPlanner::default()))
-            .with_expr_planner(Arc::new(UserDefinedFunctionPlanner))
+            .with_expr_planner(Arc::new(UnicodeFunctionPlanner))
             .with_expr_planner(Arc::new(NestedFunctionPlanner))
             .with_expr_planner(Arc::new(FieldAccessPlanner)),
     };