I have used the Calendar Object in my development and it is working well.
Questions re the way it "looks" - is it possible to make the calendar bigger? So that people can find it to click on? (I made it bright pink to make it obvious!)
The other question is - In my deveopment directory - works beautifully I can choose Mode: MultiValue and I am able to choose a week/discrete days - it works but in production it only seems to be able to pick one date? (Interstingly I can see an error in my Min Value - although this is not meant to be working?