How to make date dynamic for a report in ssrs using T-sql?

Hi ,

I have a procedure which is something like this

Now i want to use this procedure in a report and if the user picks a particular date then he must be able to see all the values for the whole month not for the day which can be done by above proc but how can i do it dynamic? how can i allow the user to only select 1 date and show all values for whole month? I cannot use start date and end date as i have to use only 1 date.

Can somebody help me with this,

Thanks.