The Spreadsheet Settings allows you to set locale and time zone settings for each spreadsheet. It is available under File > Spreadsheet settings.
When you navigate to the Spreadsheet settings, a dialog box is displayed which allows you to set the locale and time zone settings. The Locale drop-down list, displays the list of countries and the Time Zone drop-down list, diplays the different time zones. The owner of the sheet can set the Locale and Time zone for the sheet. This setting is only applied to that spreadsheet and is not dependent on the user's account settings.
Setting the Locale and Time zone for a sheet automatically sets the following: