You can set a break, or multiple breaks, for each day in the Availability section of your settings.
Select Edit next to "Set the hours you're available", then hover over the +. You will see the option to add intervals.
Add the times before the break and after. If it's the same every day, select the 'copy to all' option (the two 'pages' next to the +) and that will give you the same availability every day. Or you can create a different set-up for each day.
You can also manage availability that changes from day to day with Calendar Managed availability.