When are new online deals posted?

Hi all, I am contemplating taking my son to the point this week or the following. It's a tradition "mommy and me" day we celebrate each year around this time. I was looking at the deals online and it appears that the current ones expire 8/22. Does anyone keep track of when new deals are posted or is it usually random? I was also wondering if I should wait until the first week of September if that might be cheaper. Any insight would be appreciated, thank you!!