diff --git a/packages/backend-app-api/migrations/20240327104803_public_keys.js b/packages/backend-app-api/migrations/20240327104803_public_keys.js
index b3ee96300c..d4292c775b 100644
--- a/packages/backend-app-api/migrations/20240327104803_public_keys.js
+++ b/packages/backend-app-api/migrations/20240327104803_public_keys.js
@@ -32,8 +32,9 @@ exports.up = async function up(knex) {
 
       table.text('key').notNullable().comment('JSON serialized public key');
 
+      // Expiration is stored as a string for simplicity, all checks are done client-side
       table
-        .timestamp('expires_at')
+        .string('expires_at')
         .notNullable()
         .comment('The time that the key expires');
     },
diff --git a/packages/backend-app-api/src/services/implementations/auth/DatabaseKeyStore.test.ts b/packages/backend-app-api/src/services/implementations/auth/DatabaseKeyStore.test.ts
index f0c0d186c5..010cb68a11 100644
--- a/packages/backend-app-api/src/services/implementations/auth/DatabaseKeyStore.test.ts
+++ b/packages/backend-app-api/src/services/implementations/auth/DatabaseKeyStore.test.ts
@@ -118,7 +118,7 @@ describe('DatabaseKeyStore', () => {
           key: testKey,
           expiresAt: new Date(NaN),
         }),
-      ).rejects.toThrow('Failed to format public key expiration date');
+      ).rejects.toThrow('Invalid time value');
     });
   });
 });
diff --git a/packages/backend-app-api/src/services/implementations/auth/DatabaseKeyStore.ts b/packages/backend-app-api/src/services/implementations/auth/DatabaseKeyStore.ts
index 62e11ad991..6a1536fd18 100644
--- a/packages/backend-app-api/src/services/implementations/auth/DatabaseKeyStore.ts
+++ b/packages/backend-app-api/src/services/implementations/auth/DatabaseKeyStore.ts
@@ -28,7 +28,7 @@ export const TABLE = 'backstage_backend_public_keys__keys';
 type Row = {
   id: string;
   key: string;
-  expires_at: string | Date; // Needs parsing to handle different DB implementations
+  expires_at: string;
 };
 
 export function applyDatabaseMigrations(knex: Knex): Promise<void> {
@@ -68,14 +68,10 @@ export class DatabaseKeyStore implements KeyStore {
     key: JsonObject & { kid: string };
     expiresAt: Date;
   }) {
-    const expiresAt = DateTime.fromJSDate(options.expiresAt).toSQL();
-    if (!expiresAt) {
-      throw new Error('Failed to format public key expiration date');
-    }
     await this.client<Row>(TABLE).insert({
       id: options.key.kid,
       key: JSON.stringify(options.key),
-      expires_at: expiresAt,
+      expires_at: options.expiresAt.toISOString(),
     });
   }
 
@@ -84,7 +80,7 @@ export class DatabaseKeyStore implements KeyStore {
     const keys = rows.map(row => ({
       id: row.id,
       key: JSON.parse(row.key),
-      expiresAt: this.#parseDate(row.expires_at),
+      expiresAt: new Date(row.expires_at),
     }));
 
     const validKeys = [];
@@ -120,19 +116,4 @@ export class DatabaseKeyStore implements KeyStore {
 
     return { keys: validKeys };
   }
-
-  #parseDate(date: string | Date) {
-    const parsedDate =
-      typeof date === 'string'
-        ? DateTime.fromSQL(date, { zone: 'UTC' })
-        : DateTime.fromJSDate(date);
-
-    if (!parsedDate.isValid) {
-      throw new Error(
-        `Failed to parse date, reason: ${parsedDate.invalidReason}, explanation: ${parsedDate.invalidExplanation}`,
-      );
-    }
-
-    return parsedDate.toJSDate();
-  }
 }