Yes, instead of using a prompt in a query use a FORM for input. Then it will just read the value as many times as it needs. You should really not let your users work in tables or queries directly as you do not have the control for things as you do on forms.
I always use forms for input for these reasons as well:
1. You have more control over what the user does. You can use events to do things that opening queries by themselves do not do. So, even displaying a query is good to do in a form. And, if users like the way the query looks, you can use the datasheet view of the form to emulate it, yet still have control.
2. You can pass the information, not just once, but should the user want to re-run the same query for the same dates they won't have to re-enter the information.
3. If they accidentally type one mistake when entering it, they have to enter the entire thing over instead of just editing a value in text box.
