If you're referring to sorting tasks - that's unfortunately not possible right now, but we will consider adding such option in the future and you're welcome to vote for this request in our Votebox: http://todoist.com/Vote_iOS/showProposal/49/
For now, you can see your tasks sorted by date from all projects when you go to the "today" or "7 days" view or add any other custom date filter such as "30 days", for example.
yes i meant 'sorting' projects by date.
I can do it on the website/on my laptop but not in my iPhone.
We are talking about the same right?
Yes, that's indeed not possible on the iPhone app right now, but you're welcome to vote for it in the Votebox and we'll consider adding it in the future.