def dateof(tag_name, tags):
 for tag in tags:
  if (tag['name'] == tag_name):
   commit = read_url(tag['commit']['url'])
   return parse_timestamp(commit['commit']['committer']['date'])
 return None

def dateof ( tag_name , tags ) : for tag in tags : if ( tag [ 'name' ] == tag_name ) : commit = read_url ( tag [ 'commit' ] [ 'url' ] ) return parse_timestamp ( commit [ 'commit' ] [ 'committer' ] [ 'date' ] ) return None
given a list of tags .