diff --git a/nix-channels.py b/nix-channels.py
index fe3aee5..4ce3522 100755
--- a/nix-channels.py
+++ b/nix-channels.py
@@ -194,7 +194,11 @@ def clone_channels():
 
         tagline = node('p').text()
 
-        tagline_res = re.match(r'^Released on (.+) from', tagline)
+        # Examples:
+        #
+        # Released on yyyy-mm-dd hh:mm UTC from Git commit ...
+        # Released on yyyy-mm-dd hh:mm from ...
+        tagline_res = re.match(r'^Released on (.+?) (?:UTC )?from', tagline)
 
         if tagline_res is None:
             logging.warning(f'    - Invalid tagline: {tagline}')
@@ -385,6 +389,9 @@ def garbage_collect():
 
         channel = release.name.split('@')[0]
         date_str = (release / '.released-time').read_text()
+        date_match = re.match(r'\d+-\d+-\d+ \d+:\d+', date_str)
+        assert date_match is not None, f'Release {release!r} has invalid time {date_str!r}'
+        date_str = date_match[0]
         released_date = datetime.strptime(date_str, '%Y-%m-%d %H:%M:%S')
 
         if released_date >= time_threshold: