DateTypeProvider

F# Date Type Provider which provides strong type checking for dates.

Reason for the Type Provider

After watching this video from Scott Meyers where he showed an example of a strongly typed datetime class I thought this is a good fit for an F# Type Provider.

Example

openDateProvider// dates can be represented with month digits
Date.``2004``.``02``.``29``.ToDateTime()// or with month names
Date.``2004``.February.``29``.ToDateTime()// does not compile
Date.``2002``.``13``.``10``.ToDateTime()
Date.``2002``.``02``.``29``.ToDateTime()// you can also return a DateTimeOffset
Date.``2002``.``13``.``10``.ToDateTimeOffset()// you can also provide a century parametertypeC21= Date<century = Century.``21``>// returns years from 2001 to 2100
printfn "%A"<| C21.``2012``.November.``01``.ToDateTime()typeC18= Date<century = Century.``18``>// returns years from 1701 to 1800
printfn "%A"<| C18.``1789``.July.``14``.ToDateTime()// you can force a century even if it is not defined in the enumlet [<Literal>]c80:Century =enum80typeC80= Date<century = c80>
printfn "%A"<| C80.``7908``.July.``14``.ToDateTime()// providing a Century value which is not in the valid range (1 to 99) the provider falls back to the current centurylet [<Literal>]c100:Century =enum100typeC100= Date<century = c100>
printfn "%A"<| C100.``2004``.July.``14``.ToDateTime()

Working with NodaTime

The Type Provider returns a Date record with the Fields Year, Month and Day. You can call the methods ToDateTime() and ToDateTimeOffset(?offset) to return a DateTime or a DateTimeOffset.
Likewise you can write your own extension method to return a NodaTimeLocalDate.

openNodaTimetypeFSharp.DateTypeProvider.Datewithmemberself.ToLocalDate()=
LocalDate(self.Year, self.Month, self.Day)
printfn "%A"<| Date.``2013``.February.``01``.ToLocalDate()