diff --git a/backend/src/models/record-share.model.ts b/backend/src/models/record-share.model.ts
index 07c5523..c61d7f6 100644
--- a/backend/src/models/record-share.model.ts
+++ b/backend/src/models/record-share.model.ts
@@ -9,7 +9,7 @@ export interface RecordShareAccessLevel {
 export class RecordShare extends BaseModel {
   static tableName = 'record_shares';
 
-  // Disable automatic snake_case conversion for this table
+  // Don't use snake_case mapping since DB columns are already camelCase
   static get columnNameMappers() {
     return {
       parse(obj: any) {
@@ -21,6 +21,15 @@ export class RecordShare extends BaseModel {
     };
   }
 
+  // Override BaseModel hooks to prevent automatic timestamp handling
+  $beforeInsert(queryContext: any) {
+    // Don't set timestamps - let database defaults handle it
+  }
+
+  $beforeUpdate(opt: any, queryContext: any) {
+    // Don't set timestamps - let database defaults handle it
+  }
+
   id!: string;
   objectDefinitionId!: string;
   recordId!: string;
@@ -30,6 +39,7 @@ export class RecordShare extends BaseModel {
   expiresAt?: Date;
   revokedAt?: Date;
   createdAt!: Date;
+  updatedAt!: Date;
 
   static get jsonSchema() {
     return {
@@ -49,8 +59,22 @@ export class RecordShare extends BaseModel {
             canDelete: { type: 'boolean' },
           },
         },
-        expiresAt: { type: ['string', 'null'], format: 'date-time' },
-        revokedAt: { type: ['string', 'null'], format: 'date-time' },
+        expiresAt: {
+          anyOf: [
+            { type: 'string', format: 'date-time' },
+            { type: 'null' },
+            { type: 'object' } // Allow Date objects
+          ]
+        },
+        revokedAt: {
+          anyOf: [
+            { type: 'string', format: 'date-time' },
+            { type: 'null' },
+            { type: 'object' } // Allow Date objects
+          ]
+        },
+        createdAt: { type: ['string', 'object'], format: 'date-time' },
+        updatedAt: { type: ['string', 'object'], format: 'date-time' },
       },
     };
   }
diff --git a/backend/src/rbac/record-sharing.controller.ts b/backend/src/rbac/record-sharing.controller.ts
index 04e0102..e67726d 100644
--- a/backend/src/rbac/record-sharing.controller.ts
+++ b/backend/src/rbac/record-sharing.controller.ts
@@ -147,14 +147,16 @@ export class RecordSharingController {
 
     if (existingShare) {
       // Update existing share
-      await RecordShare.query(knex)
-        .patchAndFetchById(existingShare.id, {
-          accessLevel: {
+      await knex('record_shares')
+        .where({ id: existingShare.id })
+        .update({
+          accessLevel: JSON.stringify({
             canRead: data.canRead,
             canEdit: data.canEdit,
             canDelete: data.canDelete,
-          },
-          expiresAt: data.expiresAt ? new Date(data.expiresAt) : null,
+          }),
+          expiresAt: data.expiresAt ? data.expiresAt : null,
+          updatedAt: knex.fn.now(),
         });
 
       return RecordShare.query(knex)
@@ -163,21 +165,21 @@ export class RecordSharingController {
     }
 
     // Create new share
-    const share = await RecordShare.query(knex).insert({
+    const [shareId] = await knex('record_shares').insert({
       objectDefinitionId: objectDef.id,
       recordId,
       granteeUserId: data.granteeUserId,
       grantedByUserId: currentUser.userId,
-      accessLevel: {
+      accessLevel: JSON.stringify({
         canRead: data.canRead,
         canEdit: data.canEdit,
         canDelete: data.canDelete,
-      },
-      expiresAt: data.expiresAt ? new Date(data.expiresAt) : null,
+      }),
+      expiresAt: data.expiresAt ? data.expiresAt : null,
     });
 
     return RecordShare.query(knex)
-      .findById(share.id)
+      .findById(shareId)
       .withGraphFetched('[granteeUser]');
   }
 
@@ -233,9 +235,11 @@ export class RecordSharingController {
     }
 
     // Revoke the share (soft delete)
-    await RecordShare.query(knex)
-      .patchAndFetchById(shareId, {
-        revokedAt: new Date(),
+    await knex('record_shares')
+      .where({ id: shareId })
+      .update({
+        revokedAt: knex.fn.now(),
+        updatedAt: knex.fn.now(),
       });
 
     return { success: true };