It is important to take localization and translation into consideration from the beginning as it can become difficult and costly to apply it later. Fortunately, the platform can do a lot of work for you.
When using the native user interface, it automatically formats the values of the numeric and date fields according to the Locale field on the
user profile. Visualforce pages. Using the apex:outputField and apex:inputField components will automatically format values, and outputting local sensitive values in any other way will need to be handled manually in your Apex Controller code or in your JavaScript code.
Tip
It's not always possible to use the Visualforce apex:inputField and apex:outputField tags as described earlier in this chapter. For example, if the information you are displaying is not contained within a Custom Object field, but in some calculated view state in your Apex Controller. The format methods on various type classes such as Date, DateTime...