Time/Date range grammars

I need to parse strings containing time spans such as:

• Thursday 6:30-7:30 AM
• December 30, 2009 - January 1, 2010
• 1/15/09, 7:30 to 8:30 PM
• Thursday, from 6:30 to 7:30 AM
• and others...

added

• 6:30 to 7:30

and date/times such as most any cases that Word's insert->date can generate

As I'd be extremely surprised if anything out there covers all the cases I need to cover, I'm looking for grammars to start from.

From stackoverflow

• Ok, the following grammar parses anything in your example:

  DTExp        = Day, ['-', Day]
  Day          = DayExp, [[','], ['from'], TimeRange]
  DayExp       = WeekDay
               | [Weekday], Month, DayNumber, [[','], YearNumber]
               | [Weekday], MonthNumber, '/', DayNumber, ['/', YearNumber]
  TimeRange    = Time, [['-'|'to'] Time]
  Time         = HourNumber, ':', MinuteNumber, ['AM'|'PM']
  WeekDay      = 'monday' | 'tuesday' | ...
  Month        = MonthNumber | MonthName
  MonthName    = 'january' | 'february' | ...
  DayNumber    = Number
  MonthNumber  = Number
  YearNumber   = Number, ['AD'|'BC']
  HourNumber   = Number
  MinuteNumber = Number
  

  There is a slight problem in the grammar. If a DayExp is read, followed by a Time, and a '-', then you could expect another DayExp or another time. But this is solved by a lookahead, because if it is a time, a number is followed by a ':'.

  Lets try to construct a parse tree:

  Thursday  6    :  30     -   7    :   30    AM
      |     |        |         |         |     |
  WeekDay Number : Number  - Number : Number   |
      |     -----|----         -----|----------- 
      |         Time       -       Time
      |           ---------|---------
   DayExp              TimeRange
      ----------|-----------
               Day
                |
              DTExp
  

  BCS : Did you just generate that or is it from some other source (link?). Just curious.

  Gamecat : No, I generated that. I almost dream in grammars ;-).

  warren : @Gamecat - you need a hobby! :P

  Gamecat : Lol, I already have enough. But this I can do as the kids are asleep (at least pretending to be asleep). The others make too much noise.

  BCS : "1/2/09 from 6:30 to 7:30 - 3/16/10" Every grammar has it's insanities.