There are a few ways to do this, depending on how you are providing the date now. Before going too much farther, you might want to think about your design. There are clues in your post that suggest that there are or will be name issues and normalization. I say that because you appear to be using spaces in your names, using reserved words for names, and it looks like you have unrelated data in the same table. I/we can provide some links for further guidance on that if you need them.
To simply answer your question, I'll presume you are only supplying the beginning date as a date from your table (which also should not be in there). In that case, the DateAdd function should do what you want. The second date would be
DateAdd("d", 7, [someDate]) or DateAdd("ww",1,[someDate])
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.