Richard, thanks for the question.  "Roundup" is a brand name with different formulations.  Glyphosate (an active ingredient) alone one can plant the same day; however,  a 7 day delay before disturbing the soil will allow better control of hard to kill weeds. If there are more active ingredients, they may be more persistent and will have to be considered.  The label should indicate how long you should wait. Check out the following link:

https://www.canr.msu.edu/news/understanding_roundup_products

I hope this helps,