Not sure I'm following. I'm not seeing a delay. You've got it set to open signups 7 days before the event, which for next monday was 7pm tonight. Every event's signups will be locked until exactly 7 days (168 hours) before the start of the event.
What do you mean by a "delayed signup day"?
What I mean by that is the delay before alloing people to dign up. I.E. You delay signups until X days before the event.
When I first made this post, only the Monday entries were following this rule. When you opened them, they showed the same graphic you posted above.
However every Thursday and Sunday in the future, which should show the same graphic, was taking you to a normal sign up prompt for that calendar entry. I.E. The 7 day lockout/delay/whatever was only working for the Mondays.
Checking again just now, all signups more than 7 days out are showing the lockout graphic you posted.
I swear I am not making this up because it was guildies asking me (the care taker of the site) why only mondays in the future were locked out and not the rest. I saw the same thing they did.