Zwift says my plan is available at 19:00. It is 17:30 now and I am ready and waiting.
Is your concern that you’re wanting to do the Training Plan workout earlier than the time it’s listed as being available? If so, then I’m sorry to say that’s not currently possible.
I expect that you should be able to start the next workout once it shows as as being available. It sounds like you’ve got less than an hour before the week 5 workouts are available for you.
For general answers to common questions about Training Plans, see this article.