Each resource can be made available during all or just some hours. To set the hours, click Edit for the resource to update this.
By setting the Working Hours you can ensure that they won't be available to select outside of these hours. These hours can be set differently between Bookings, Waitlist or both depending on which the Resource is available to.
If your Resource has custom hours for a specific period of time, consider adjusting these hours by setting their Hours by Date. These Hours by Date will override their set working hours for the specified date range.