Error when changing a group in code

I am getting the following error message when i attempt to set a date field as the group by condition in code.



"The group options for a date, time or date-time condition field must be a date group options object."



Does anyone know what this means or how it can be corrected? Im using VS2005 and ASP.NET

ThanksWell, I'm guessing that you need to provide a valid group option :)
i.e. do you want the dates grouped by day, week, month etc.|||Thanks for your reply. Yes it would seem i would need to set a valid group option but i think firstly for a group field that is using a date/time field the groupOptions property needs to be of type DateTimeGroupOptions. If originally the grouped field was a not date field you can't then change it to a date/time field because the GroupOptions property is Read-Only and can't be changed to the DateTimeGroupOptions object.