Depending on your needs, you may need to adjust the Regional Settings for your SharePoint site. These include such things as Time Zone, Locale, Calendar, Work Week, etc.
To alter these settings you must be an administrator of your site. The settings are site-wide.
- Login to your site
- Click the Settings menu and select Site Settings
- In the Site Administration section, click Regional settings
- Adjust the settings as needed and click OK to save your changes