diff --git a/src/components/admin/ParkForm.tsx b/src/components/admin/ParkForm.tsx
index 5f500105..1825521b 100644
--- a/src/components/admin/ParkForm.tsx
+++ b/src/components/admin/ParkForm.tsx
@@ -262,7 +262,7 @@ export function ParkForm({ onSubmit, onCancel, initialData, isEditing = false }:
               <Label>Opening Date</Label>
               <DatePicker
                 date={watch('opening_date') ? new Date(watch('opening_date')) : undefined}
-                onSelect={(date) => setValue('opening_date', date ? date.toISOString().split('T')[0] : '')}
+                onSelect={(date) => setValue('opening_date', date ? date.toISOString().split('T')[0] : undefined)}
                 placeholder="Select opening date"
                 disableFuture={true}
                 fromYear={1800}
@@ -273,7 +273,7 @@ export function ParkForm({ onSubmit, onCancel, initialData, isEditing = false }:
               <Label>Closing Date (if applicable)</Label>
               <DatePicker
                 date={watch('closing_date') ? new Date(watch('closing_date')) : undefined}
-                onSelect={(date) => setValue('closing_date', date ? date.toISOString().split('T')[0] : '')}
+                onSelect={(date) => setValue('closing_date', date ? date.toISOString().split('T')[0] : undefined)}
                 placeholder="Select closing date"
                 disablePast={false}
                 fromYear={1800}
diff --git a/src/components/admin/RideForm.tsx b/src/components/admin/RideForm.tsx
index eb41139c..bfbcdf35 100644
--- a/src/components/admin/RideForm.tsx
+++ b/src/components/admin/RideForm.tsx
@@ -523,7 +523,7 @@ export function RideForm({ onSubmit, onCancel, initialData, isEditing = false }:
               <Label>Opening Date</Label>
               <DatePicker
                 date={watch('opening_date') ? new Date(watch('opening_date')) : undefined}
-                onSelect={(date) => setValue('opening_date', date ? date.toISOString().split('T')[0] : '')}
+                onSelect={(date) => setValue('opening_date', date ? date.toISOString().split('T')[0] : undefined)}
                 placeholder="Select opening date"
                 disableFuture={true}
                 fromYear={1800}
@@ -534,7 +534,7 @@ export function RideForm({ onSubmit, onCancel, initialData, isEditing = false }:
               <Label>Closing Date (if applicable)</Label>
               <DatePicker
                 date={watch('closing_date') ? new Date(watch('closing_date')) : undefined}
-                onSelect={(date) => setValue('closing_date', date ? date.toISOString().split('T')[0] : '')}
+                onSelect={(date) => setValue('closing_date', date ? date.toISOString().split('T')[0] : undefined)}
                 placeholder="Select closing date"
                 disablePast={false}
                 fromYear={1800}
diff --git a/supabase/functions/process-selective-approval/index.ts b/supabase/functions/process-selective-approval/index.ts
index c08d59c0..1e0d7a0f 100644
--- a/supabase/functions/process-selective-approval/index.ts
+++ b/supabase/functions/process-selective-approval/index.ts
@@ -196,6 +196,19 @@ function resolveDependencies(data: any, dependencyMap: Map<string, string>): any
   return resolved;
 }
 
+function sanitizeDateFields(data: any): any {
+  const dateFields = ['opening_date', 'closing_date', 'date_changed', 'date_taken', 'visit_date'];
+  const sanitized = { ...data };
+  
+  for (const field of dateFields) {
+    if (field in sanitized && sanitized[field] === '') {
+      sanitized[field] = null;
+    }
+  }
+  
+  return sanitized;
+}
+
 async function createPark(supabase: any, data: any): Promise<string> {
   // Transform images object if present
   if (data.images) {
@@ -225,18 +238,20 @@ async function createPark(supabase: any, data: any): Promise<string> {
     const parkId = data.park_id;
     delete data.park_id; // Remove ID from update data
     
+    const sanitizedData = sanitizeDateFields(data);
     const { error } = await supabase
       .from('parks')
-      .update(data)
+      .update(sanitizedData)
       .eq('id', parkId);
 
     if (error) throw new Error(`Failed to update park: ${error.message}`);
     return parkId;
   } else {
     console.log('Creating new park');
+    const sanitizedData = sanitizeDateFields(data);
     const { data: park, error } = await supabase
       .from('parks')
-      .insert(data)
+      .insert(sanitizedData)
       .select('id')
       .single();
 
@@ -274,18 +289,20 @@ async function createRide(supabase: any, data: any): Promise<string> {
     const rideId = data.ride_id;
     delete data.ride_id; // Remove ID from update data
     
+    const sanitizedData = sanitizeDateFields(data);
     const { error } = await supabase
       .from('rides')
-      .update(data)
+      .update(sanitizedData)
       .eq('id', rideId);
 
     if (error) throw new Error(`Failed to update ride: ${error.message}`);
     return rideId;
   } else {
     console.log('Creating new ride');
+    const sanitizedData = sanitizeDateFields(data);
     const { data: ride, error } = await supabase
       .from('rides')
-      .insert(data)
+      .insert(sanitizedData)
       .select('id')
       .single();
 
@@ -322,7 +339,7 @@ async function createCompany(supabase: any, data: any, companyType: string): Pro
   
   if (companyId) {
     console.log(`Updating existing company ${companyId}`);
-    const updateData = { ...data, company_type: companyType };
+    const updateData = sanitizeDateFields({ ...data, company_type: companyType });
     delete updateData.company_id;
     delete updateData.id; // Remove ID from update data
     
@@ -335,7 +352,7 @@ async function createCompany(supabase: any, data: any, companyType: string): Pro
     return companyId;
   } else {
     console.log('Creating new company');
-    const companyData = { ...data, company_type: companyType };
+    const companyData = sanitizeDateFields({ ...data, company_type: companyType });
     const { data: company, error } = await supabase
       .from('companies')
       .insert(companyData)