Add a field to your query to format the date into a column that you can use to group by.
Select ..., Format(YourDate, "yyyy-mm") as GroupByMonth, Format(YourDate, "mmm") As MonthName
From YourTable;
Use GroupByMonth as your sorting/grouping option. You'll need to add the field as a hidden control in the group header. Add MonthName as a visible control in the header section. If you will have multi-year data, include year in the visible month name field.
i have check_in_date in booking table,,,,,,, so i want to group booking information on month wise ,,,, mean the booking which are done in april are separate group and may are separate etc