How can PHP developers ensure that date and time functions display the correct language output?

PHP developers can ensure that date and time functions display the correct language output by setting the desired language using the `setlocale()` function before calling any date or time functions. This function sets the locale information for date and time functions, such as the language, region, and encoding. By setting the locale to the desired language, developers can ensure that date and time functions will display output in the specified language.

// Set the locale to the desired language (e.g., French)
setlocale(LC_TIME, 'fr_FR');

// Display the current date and time in the specified language
echo strftime('%A %d %B %Y %H:%M:%S');