This function returns the absolute URI for the partial URL passed. The current scheme (HTTP/HTTPS), host server, port, current script location are used if necessary to resolve any relative URLs.
Offsets potentially created by PATH_INFO are taken care of to resolve relative URLs to the current script.
You can choose a new protocol while resolving the URI. This is particularly useful when redirecting a web browser using relative URIs and to switch from HTTP to HTTPS, or vice-versa, at the same time.
Format a RFC compliant GMT date HTTP header. This function honors the "y2k_compliance" php.ini directive and formats the GMT date corresponding to either RFC850 or RFC822.
Return: GMT date string, or false for an invalid $time parameter
Negotiate language with the user's browser through the Accept-Language HTTP header or the user's host address. Language codes are generally in the form "ll" for a language spoken in only one country, or "ll-CC" for a language spoken in a particular country. For example, U.S. English is "en-US", while British English is "en-UK". Portugese as spoken in Portugal is "pt-PT", while Brazilian Portugese is "pt-BR".
Quality factors in the Accept-Language: header are supported, e.g.: Accept-Language: en-UK;q=0.7, en-US;q=0.6, no, dk;q=0.8