How come my Django filter isn't working?

Question

Submitted on {{ post.date|date:"D. M d, P" }}
Submitted {{ post.date|timesince }} ago

The timesince filter does not work.

Submitted on Tue. Jan 04, 9:45 p.m. 
Submitted 0 minutes ago

As you can see , the date filter works, but timesince does not.

Answer 1

也许将来是post.date ？