def parse_date(ims):
try:<EOL><INDENT>ts = email.utils.parsedate_tz(ims)<EOL>return time.mktime(ts[:<NUM_LIT:8>] + (<NUM_LIT:0>, )) - (ts[<NUM_LIT:9>] or <NUM_LIT:0>) - time.timezone<EOL><DEDENT>except (TypeError, ValueError, IndexError, OverflowError):<EOL><INDENT>return None<EOL><DEDENT>
Parse rfc1123, rfc850 and asctime timestamps and return UTC epoch.