You may need to change your user's next invoice date associated with a subscription for a variety of reasons. To make those changes, you will need to access the detailed view of a user's account.
To edit the invoice date, navigate the People tab, and under the second People tab, find the user you want to edit the dates for and click Edit. Under the Access section, go to the Subscription tab and click on the 3 vertical dots (⋮) menu on their active subscription plan (which is highlighted in green), then click on Edit.
To change the date and time, simply click on each field and choose the new one. Lastly, click on Save changes.
NOTE: The script that generates invoices is run twice per day—once at 9 am EST and once at 4 pm EST. If you are adjusting the next payment date/time in order to generate an invoice, please be aware of these times as it may take several hours for the invoice to generate depending on the time selected in the next payment date.