+dateTime ∷ Parser ZonedTime
+dateTime = do weekDay ← optionMaybe $
+ do w ← shortWeekDayNameP
+ _ ← string ", "
+ return w
+ gregDay ← date
+ case weekDay of
+ Nothing
+ → return ()
+ Just givenWD
+ → assertWeekDayIsGood givenWD gregDay
+ (tod, timeZone) ← rfc822Time
+ let lt = LocalTime gregDay tod
+ zt = ZonedTime lt timeZone
+ return zt
+
+date ∷ Parser Day
+date = do day ← read2
+ _ ← char ' '
+ month ← shortMonthNameP
+ _ ← char ' '
+ year ← read4
+ _ ← char ' '
+ assertGregorianDateIsGood year month day
+
+toAsciiBuilder ∷ ZonedTime → AsciiBuilder
+toAsciiBuilder zonedTime