You can edit a 1:1 schedule from both the overview page and the meeting page.

To do so, you must have created it.

Overview page

To start editing from the overview page, click the edit icon highlighted below.

Meeting page

To start editing from the meeting page, open the calendar tab in the sidebar and then click the dropdown icon highlighted below. You can then click edit schedule.

Regardless of what method you use, you will be presented with the following page.

Here, you can change any information about your 1:1 schedule that you defined during creation.

See here for information on how to configure a 1:1 schedule.

Just the next meeting

If you want to edit the schedule, but just for the next meeting in the 1:1 schedule, you can do so by enabling the Just next meeting slider.

Doing so will ensure that your changes only apply to the next meeting in the schedule.