Every site (both top-level Web sites and subsites) can be customized to use specific regional settings that are used as the default regional settings for all users of your site. Individual users can choose to use the default settings set by the site owner or specify their own personal settings. You can specify the following regional settings:
Follow Web Settings This setting always uses the default regional settings that were set by the site owner.
Locale This setting controls how locale-specific information, such as numbers, dates, time, and calendar settings, is displayed on the site. The default values for all of the other regional settings (listed below) are based on the locale that you choose. When you change the locale setting for a site, all other regional settings are set to the default settings for the new locale. After selecting the locale that you want, you can then change these other settings as you want.
Time Zone This setting controls the time zone for the Web site.
Set Your Calendar This setting specifies the type of calendar that you want as your primary calendar. You can also choose whether to display the week of the year, where 1 represents the first week of the year and 52 represents the last week of the year.
Enable An Alternate Calendar This setting enables the settings of an optional calendar to be added to the calendar that you set for your site.
Define Your Work Week This setting specifies which days of the week make up your work week, the first day of each work week, and the first week of the year. You can also specify the start and end time of work days.
Time Format This setting specifies whether to display the time in 12-hour or 24-hour format.
Note: Depending on what locale you selected, you may be able to select only the 24-hour time format.
Change the regional settings for a site
Do the following on each SharePoint site on which you want to configure personal regional settings:
Open the site on which you want to configure your personal regional settings.
At the top of the site, click the arrow next to Welcome User name, and then click My Settings.
On the User Information page, click My Regional Settings.
On the Regional Settings page, in the Follow Web Settings section, clear the Always follow web settings check box.
Select the settings that you want for this site, and then click OK.