You can add your audience to a list using Automation.
From the Automation tab -> Your Automations – > Create Automation.
To create the automation, choose the Specific Date trigger and link it to Add to list Action.
In the trigger configuration, choose the audience you want to add to the list and a date to launch the automation.
In the Action configuration, choose the list you want to add your audience to.
Save the automation and publish it.
After the automation is completed, the contacts will be added to the chosen list.