General availability is a field in the profile card and a form field that you can add to your signup forms.
Availability can be edited in the volunteer's profile card without entering edit mode - simply click the availability boxes. Availability is also automatically updated when your volunteers fill out a form that you've created which contains the availability field.
Currently, the timeframe for availability cannot be edited - it is as appears: Monday - Sunday; morning, afternoon, and evening. We have great plans for this feature, and will keep you updated as it evolves.
Asking for the general availability of your volunteers is a great way to keep track of who has time throughout the week to help.