Add exact timestamp to Reddit submission data dictionary

This will enable easy implementation of the exact timestamp display as
requested in #3

tests/test_content.py

@@ -142,6 +142,27 @@ def test_content_humanize_timestamp():
     assert Content.humanize_timestamp(timestamp, True) == '2 years ago'
 
 
+def test_content_exact_timestamp():
+    # Less than a year ago.
+    timestamp = time.time() - 60 * 60
+
+    # Calling datetime.strftime("%m-%d %H:%M") should always give a string of
+    # length 11
+    assert len(Content.exact_timestamp(timestamp)) == 11
+
+    timestamp = time.time() - 60 * 60 * 24 * 31 * 12 * 2
+
+    # Similarly, calling datetime.strftime("%Y-%m-%d") should always give a
+    # string of length 10
+    assert len(Content.exact_timestamp(timestamp)) == 10
+
+    # Does it break on a leap day?
+    from datetime import datetime
+    leapday = (datetime(2016, 2, 29) - datetime(1970, 1, 1)).total_seconds()
+
+    Content.exact_timestamp(leapday)
+
+
 def test_content_wrap_text():
 
     text = 'four score\nand seven\n\n'

tuir/content.py

@@ -233,6 +233,7 @@ class Content(object):
         data['html'] = sub.selftext_html or ''
         data['created'] = cls.humanize_timestamp(sub.created_utc)
         data['created_long'] = cls.humanize_timestamp(sub.created_utc, True)
+        data['created_exact'] = cls.exact_timestamp(sub.created_utc)
         data['comments'] = sub.num_comments
         data['score'] = '{0}'.format('-' if sub.hide_score else sub.score)
         data['author'] = name
@@ -253,9 +254,12 @@ class Content(object):
                 cls.humanize_timestamp(sub.edited))
             data['edited_long'] = '(edit {})'.format(
                 cls.humanize_timestamp(sub.edited, True))
+            data['edited_exact'] = '(edit {})'.format(
+                cls.exact_timestamp(sub.edited))
         else:
             data['edited'] = ''
             data['edited_long'] = ''
+            data['edited_exact'] = ''
 
         if sub.url.split('/r/')[-1] == sub.permalink.split('/r/')[-1]:
             data['url'] = 'self.{0}'.format(data['subreddit'])
@@ -398,6 +402,18 @@ class Content(object):
         else:
             return '%dyr' % years
 
+    @staticmethod
+    def exact_timestamp(utc_timestamp):
+        dt = datetime.fromtimestamp(utc_timestamp)
+
+        # https://stackoverflow.com/a/765990
+        yearsago = ((datetime.now() - dt).days / 365.2425)
+
+        if yearsago > 0:
+            return dt.strftime("%Y-%m-%d")
+        else:
+            return dt.strftime("%m-%d %H:%M")
+
     @staticmethod
     def wrap_text(text, width):
         """