title: Django - Can't load custom filter in templates
body: <p>I want to show delta time as 'x days ago'. I tried Django's timesince filter, but it returns 'x days, x minutes'. I want to show only days. I tried humanize's naturaltime, but I guess its only for DateTimeField. I'm using DateField.</p>
  
  <p>I have a custom filter like this (app_filters.py);</p>
  
  <pre><code>from django import template
  from datetime import date
  
  register = template.Library()
  
  
  @register.filter(name='days_since')
  def days_since(value):
      delta = value - date.today()
  
      if delta.days == 0:
          return 'Today'
      elif delta.days &lt; 1:
          return '{} days ago'.format(abs(delta.days))
      elif delta.days == 1:
          return 'Tomorrow'
      elif delta.days &gt; 1:
          return 'In {} days'.format(delta.days)
  </code></pre>
  
  <p>This is application folder;</p>
  
  <pre><code>app/
      models.py
      views.py
      ...
      templatetags/
          __init__.py
          app_filters.py
  </code></pre>
  
  <p>I added the 'app' to INSTALLED_APPS in settings.py
  I'm trying to use this filter in templates like this;</p>
  
  <pre><code>{% extends 'app/base.html' %}
  {% load app_filters %}
  
  {{ entry.date_updated | days_since }}
  </code></pre>
  
  <p>Then I get the error: 'app_filters' is not a registered tag library. </p>
  
  <p>Where is my mistake?</p>