You can edit Smart 1:1s at any time if you want to change scheduling preferences, the description, or any other facet of the 1:1 besides the attendee.
How to edit Smart 1:1s
From the list of Smart 1:1s, click on the card to open the details view for the 1:1, then click Edit:
From here, you can edit any details you'd like to change about the 1:1, excluding the attendee. Once you're done, click Save Changes.
Within a few minutes, your 1:1s will update to reflect your new preferences.