How to inform search engines that the downtime is temporary

503 Service Unavailable, that informs the search engines that the server is temporarily unavailable. To do this one must first create a file that returns a 503 status code on the server. When the search engine sees this, it will understand the situation. This can be done by copying the four lines below into Notepad (or the like) and saving it as 503.php. You must then place this file in the root of your server.
The first two lines tell us that it is a 503 status code, and the last line is used to tell when the website is expected to be online again. Google understands this message, so it is possible to tell Google when to visit the website again. You must either provide a number (seconds) or a date. If you live in Denmark like I do and you expect to return on the 5th of January 2012, at 14:00, you must put down: