diff --git a/code/core/src/telemetry/anonymous-id.test.ts b/code/core/src/telemetry/anonymous-id.test.ts
index 8277ca547e85..cdee088797ab 100644
--- a/code/core/src/telemetry/anonymous-id.test.ts
+++ b/code/core/src/telemetry/anonymous-id.test.ts
@@ -1,6 +1,27 @@
-import { describe, expect, it } from 'vitest';
+import { beforeEach, describe, expect, it, vi } from 'vitest';
 
-import { normalizeGitUrl, unhashedProjectId } from './anonymous-id';
+import { executeCommandSync } from 'storybook/internal/common';
+
+import {
+  getAnonymousProjectId,
+  getProjectSince,
+  normalizeGitUrl,
+  unhashedProjectId,
+} from './anonymous-id';
+
+vi.mock(import('storybook/internal/common'), async (actualModule) => {
+  const actual = await actualModule();
+
+  return {
+    ...actual,
+    executeCommandSync: vi.fn(actual.executeCommandSync),
+    getProjectRoot: () => '/path/to/project/root',
+  };
+});
+
+beforeEach(() => {
+  vi.mocked(executeCommandSync).mockReset();
+});
 
 describe('normalizeGitUrl', () => {
   it('trims off https://', () => {
@@ -105,3 +126,64 @@ describe('unhashedProjectId', () => {
     ).toBe('github.com/storybookjs/storybook.gitpath/to/storybook');
   });
 });
+
+describe('getProjectSince', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    vi.resetModules();
+  });
+
+  it('returns the Storybook creation date from git log output', () => {
+    vi.mocked(executeCommandSync).mockReturnValue(
+      '2025-12-11 16:24:01 +0530\n' + '2014-12-11 19:09:10 +0530'
+    );
+
+    expect(getProjectSince()).toEqual(new Date('2025-12-11T10:54:01.000Z'));
+  });
+
+  it('returns undefined if git log output is empty', async () => {
+    vi.mocked(executeCommandSync).mockReturnValue('');
+
+    const { getProjectSince: getProjSince } = await import('./anonymous-id');
+
+    expect(getProjSince()).toBeUndefined();
+  });
+
+  it('returns undefined if git log fails', async () => {
+    vi.mocked(executeCommandSync).mockImplementation(() => {
+      throw new Error('git not available');
+    });
+
+    const { getProjectSince: getProjSince } = await import('./anonymous-id');
+
+    expect(getProjSince()).toBeUndefined();
+  });
+});
+
+describe('getAnonymousProjectId', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    vi.resetModules();
+
+    vi.spyOn(process, 'cwd').mockReturnValue('/path/to/project/root');
+  });
+
+  it('returns hashed project id for Storybook repo when git command succeeds', async () => {
+    vi.mocked(executeCommandSync).mockReturnValue('git@github.com:storybookjs/storybook.git');
+    const result = getAnonymousProjectId();
+
+    expect(result).toMatch('061e4ee22a1f7c079849d97234b3be94d016fb1f24ba11878c41f8b48c0213bf');
+  });
+
+  it('returns undefined when git command fails', async () => {
+    const { getAnonymousProjectId: getAnonId } = await import('./anonymous-id');
+
+    vi.mocked(executeCommandSync).mockImplementation(() => {
+      throw new Error('git not available');
+    });
+
+    const result = getAnonId();
+
+    expect(result).toBeUndefined();
+  });
+});
diff --git a/code/core/src/telemetry/anonymous-id.ts b/code/core/src/telemetry/anonymous-id.ts
index 951a268a6263..a66fb88f0538 100644
--- a/code/core/src/telemetry/anonymous-id.ts
+++ b/code/core/src/telemetry/anonymous-id.ts
@@ -1,8 +1,7 @@
 import { relative } from 'node:path';
 
-import { getProjectRoot } from 'storybook/internal/common';
+import { executeCommandSync, getProjectRoot } from 'storybook/internal/common';
 
-import { execSync } from 'child_process';
 // eslint-disable-next-line depend/ban-dependencies
 import slash from 'slash';
 
@@ -33,6 +32,8 @@ export function unhashedProjectId(remoteUrl: string, projectRootPath: string) {
 }
 
 let anonymousProjectId: string;
+let getProjectSinceResult: Date | undefined;
+
 export const getAnonymousProjectId = () => {
   if (anonymousProjectId) {
     return anonymousProjectId;
@@ -41,15 +42,45 @@ export const getAnonymousProjectId = () => {
   try {
     const projectRootPath = relative(getProjectRoot(), process.cwd());
 
-    const originBuffer = execSync(`git config --local --get remote.origin.url`, {
+    const result = executeCommandSync({
+      command: 'git',
+      args: ['config', '--get', 'remote.origin.url'],
       timeout: 1000,
-      stdio: `pipe`,
     });
 
-    anonymousProjectId = oneWayHash(unhashedProjectId(String(originBuffer), projectRootPath));
+    anonymousProjectId = oneWayHash(unhashedProjectId(result, projectRootPath));
   } catch (_) {
     //
   }
 
   return anonymousProjectId;
 };
+
+export const getProjectSince = () => {
+  try {
+    if (getProjectSinceResult) {
+      return getProjectSinceResult;
+    }
+
+    const dateBuffer = executeCommandSync({
+      command: 'git',
+      args: ['log', '--reverse', '--format=%cd', '--date=iso'],
+      timeout: 1000,
+    });
+
+    const firstLine = String(dateBuffer).trim().split('\n')[0];
+
+    const date = new Date(firstLine);
+
+    if (Number.isNaN(date.getTime())) {
+      return undefined;
+    }
+
+    getProjectSinceResult = date;
+    return date;
+  } catch (_) {
+    //
+  }
+
+  return undefined;
+};
diff --git a/code/core/src/telemetry/telemetry.ts b/code/core/src/telemetry/telemetry.ts
index b84ae26b47ac..cb5b903cd085 100644
--- a/code/core/src/telemetry/telemetry.ts
+++ b/code/core/src/telemetry/telemetry.ts
@@ -10,7 +10,7 @@ import { nanoid } from 'nanoid';
 
 import { version } from '../../package.json';
 import { resolvePackageDir } from '../shared/utils/module';
-import { getAnonymousProjectId } from './anonymous-id';
+import { getAnonymousProjectId, getProjectSince } from './anonymous-id';
 import { detectAgent } from './detect-agent';
 import { set as saveToCache } from './event-cache';
 import { fetch } from './fetch';
@@ -107,6 +107,7 @@ export async function sendTelemetry(
     : {
         ...globalContext,
         anonymousId: getAnonymousProjectId(),
+        projectSince: getProjectSince()?.getTime(),
       };
 
   let request: any;
diff --git a/docs/configure/telemetry.mdx b/docs/configure/telemetry.mdx
index 2d25e6d7ddeb..4aacc45029e7 100644
--- a/docs/configure/telemetry.mdx
+++ b/docs/configure/telemetry.mdx
@@ -62,6 +62,14 @@ Will generate the following output:
 {
   "anonymousId": "8bcfdfd5f9616a1923dd92adf89714331b2d18693c722e05152a47f8093392bb",
   "eventType": "dev",
+  "context": {
+    "isTTY": true,
+    "platform": "macOS",
+    "nodeVersion": "24.11.0",
+    "storybookVersion": "10.3.0-alpha.9",
+    "cliVersion": "10.3.0-alpha.9",
+    "projectSince": 1717334400000
+  },
   "payload": {
     "versionStatus": "cached",
     "storyIndex": {