Wait step

I'd like to set up an alert to go out on the same day at 6pm ET if a certain field has not been updated.  My wait step is:

Type:  Date Token
End on: {{system.date}} 
Time:  6PM

Will this work for all leads going through the flow before 6pm?  What can I do with leads going through the flow after 6pm and have them not end on a weekend?  Thoughts?

Thanks.