How to run a protractor browser.sleep for 15 minutes

I have to run some tests agains a live site. I have to pretty much just make tasks to wait on a website to time out (15 minutes), then run another task, once that has passed. the longest i got it to wait is 26.6 seconds (26600 ms) on firefox, and about 30 on chrome.

I get the following error :

Error: Timeout - Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL.

so basically i need adjust the specified timeout from jasmine to run this:

 browser.get('www.page.com');
 browser.sleep(900000);
 browser.doSomethingElse();