diff --git a/lib/index.js b/lib/index.js
index 78c8998..a4fb23a 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -232,6 +232,7 @@ export async function runUserCommand(post, client, store, msg, data) {
 const commandGroupFetchBodySchema = {
     type: 'object',
     properties: {
+        nextFetchDate: { type: 'string', format: 'date-time' },
         commands: {
             type: 'array',
             items: {
@@ -244,7 +245,7 @@ const commandGroupFetchBodySchema = {
             }
         }
     },
-    required: ['commands']
+    required: ['commands', 'nextFetchDate']
 };
 
 export async function fetchAndAddCommandsFromGroup({ get, store }, groupId) {
@@ -254,14 +255,11 @@ export async function fetchAndAddCommandsFromGroup({ get, store }, groupId) {
 
         console.log(`Fetching commands from group ${groupId} with URL ${url}`);
 
-        const { headers, body } = await get(url);
+        const { body } = await get(url);
 
-        const { instance: { commands } } = validate(body, commandGroupFetchBodySchema, { required: true, throwAll: true });
+        const { instance: { nextFetchDate: nextFetchDateStr, commands } } = validate(body, commandGroupFetchBodySchema, { required: true, throwAll: true });
 
-        const nextFetchDate = new Date(headers.get('Next-Fetch-Date'));
-        if (Number.isNaN(+nextFetchDate)) {
-            throw new Error('Unable to parse date from header Next-Fetch-Date');
-        }
+        const nextFetchDate = new Date(nextFetchDateStr);
 
         await store.set('command-groups', {
             ...groups,
diff --git a/test/fetch-and-add-commands-from-group.js b/test/fetch-and-add-commands-from-group.js
index f386284..defc0b0 100644
--- a/test/fetch-and-add-commands-from-group.js
+++ b/test/fetch-and-add-commands-from-group.js
@@ -14,10 +14,9 @@ test('works', async t => {
     const { get, store } = t.context;
 
     get.resolves({
-        headers: new Headers({
-            'Next-Fetch-Date': '2024-05-09T01:02:03.000Z'
-        }),
+        headers: new Headers(),
         body: {
+            nextFetchDate: '2024-05-09T01:02:03.000Z',
             commands: [
                 { name: 'some-command', url: '/some-command' },
                 { name: 'another-command', url: '/another-command' },
@@ -52,10 +51,9 @@ test('throws error on malformed GET response', async t => {
     const { get, store } = t.context;
 
     get.resolves({
-        headers: new Headers({
-            'Next-Fetch-Date': '2024-05-09T01:02:03.000Z'
-        }),
+        headers: new Headers(),
         body: {
+            nextFetchDate: 'wowie',
             someRandomStuff: 'cool'
         }
     });
@@ -71,29 +69,3 @@ test('throws error on malformed GET response', async t => {
     t.true(err.message.startsWith(`When running fetchAndAddCommandsFromGroup for group ${groupId}:`));
     t.snapshot(err.cause.errors);
 });
-
-test('throws error on malformed date in Next-Fetch-Date header', async t => {
-    const { get, store } = t.context;
-
-    get.resolves({
-        headers: new Headers({
-            'Next-Fetch-Date': 'something random'
-        }),
-        body: {
-            commands: [
-                { name: 'some-command', url: '/some-command' },
-                { name: 'another-command', url: '/another-command' },
-            ]
-        }
-    });
-
-    await store.set('command-groups', {
-        [groupId]: {
-            url: 'https://example.com/.commands',
-            commands: []
-        }
-    });
-
-    const err = await t.throwsAsync(() => fetchAndAddCommandsFromGroup({ get, store }, groupId));
-    t.is(err.message, `When running fetchAndAddCommandsFromGroup for group ${groupId}: Unable to parse date from header Next-Fetch-Date`);
-});
diff --git a/test/snapshots/fetch-and-add-commands-from-group.js.md b/test/snapshots/fetch-and-add-commands-from-group.js.md
index f46eca7..a85d9ea 100644
--- a/test/snapshots/fetch-and-add-commands-from-group.js.md
+++ b/test/snapshots/fetch-and-add-commands-from-group.js.md
@@ -9,9 +9,25 @@ Generated by [AVA](https://avajs.dev).
 > Snapshot 1
 
     [
+      ValidationError {
+        argument: 'date-time',
+        instance: 'wowie',
+        message: 'does not conform to the "date-time" format',
+        name: 'format',
+        path: [
+          'nextFetchDate',
+        ],
+        property: 'instance.nextFetchDate',
+        schema: {
+          format: 'date-time',
+          type: 'string',
+        },
+        stack: 'instance.nextFetchDate does not conform to the "date-time" format',
+      },
       ValidationError {
         argument: 'commands',
         instance: {
+          nextFetchDate: 'wowie',
           someRandomStuff: 'cool',
         },
         message: 'requires property "commands"',
@@ -38,20 +54,17 @@ Generated by [AVA](https://avajs.dev).
               },
               type: 'array',
             },
+            nextFetchDate: {
+              format: 'date-time',
+              type: 'string',
+            },
           },
           required: [
             'commands',
+            'nextFetchDate',
           ],
           type: 'object',
         },
         stack: 'instance requires property "commands"',
       },
     ]
-
-## throws error on malformed date in Next-Fetch-Date header
-
-> Snapshot 1
-
-    Error {
-      message: 'Unable to parse date from header Next-Fetch-Date',
-    }
diff --git a/test/snapshots/fetch-and-add-commands-from-group.js.snap b/test/snapshots/fetch-and-add-commands-from-group.js.snap
index aff5680..e2a2505 100644
Binary files a/test/snapshots/fetch-and-add-commands-from-group.js.snap and b/test/snapshots/fetch-and-add-commands-from-group.js.snap differ