[Haskell-cafe] Example for formatted show in HStringTemplate

Hello, is there a working example of how to use the format clause with HStringTemplate, e.g. for Data.Time.Day? I think, if there is a parameter $day$, a reasonable template might contain e.g.: $day;format="%d.%b.%Y"$ But I only get "toModifiedJulianDay: [54960]" as the result which corresponds to the unformatted show. Regards, Torsten