Query of consultants and their expected payments for the month
you are doing a lot of CONVERTing in this query.   

Instead of converting the Date variables inside the WHERE clause you should do that before you even start the query, otherwise you are running this convert for every row in the SELECT because the WHERE decides if a row should be kept or discarded from the returned table.



Are the date fields not already in DateTime format?

get rid of all the Converts that are not needed.



also you should format your code with some indentation so that it is easier to read, for you and for others who will maintain the code you write.