You are able to allow customers to sign up in a wait list for multiple simultaneous dates at one time.

From the Set up page, select on the wait list option, which then allows you to enable the "Limit the duration that a customer can join the wait list for":

The time you have set is in days, which means that this is the maximum days they can sign up a wait list for.
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For eg. if you have set this to 25 days, a customer that didn't see any available times that they preferred are able to sign up for a wait list within the the next 25 days at once.

Here is a sample on how it shows up on the customer's end.

After a customer selects the service, they can select on the button at top which allows them to sign up and join for the wait list:

From there, they should be able to sign up the form, and they can customize the dates that they would like to sign up for:

After they save the wait list, they would receive a notification for the wait list. (Alerting customers are completely optional as well, which you can customize)