For each resource a specific project calendar can be set based on his working times like –standard, 24 hours, night shift or any customized calendar made for the project. Within the specific calendar set for a resource we can set up the individual resource’s schedule. We can mark holiday periods of the resource, change the working hours for a particular resource and also set the working / non-working days. All these are set on the calendar of the resource, but, no changes are made to the general base calendar which is common to the project.
MS Project tutorial - GROOK Network