I agree with the others.
We experienced grout color differences when we did grout in smaller batches.
Each batch was slightly different. You could run into the same issue if its
days apart. Less messy if you wait and do it all at once.

Scott-
"Joe" wrote in message
oups.com...
I still have to cut and lay the tiles around the edges. I'm probably
not going to get to it today or this week. Is it bad to grout the part
that's done and grout the rest of it at a later date? Will a seam show
or will it be weakened where the old grout and new grout meet?