How long does google accept a "site maintenance" page

[baron13]

Hi,
our webhosting comopany is experiencing problems with their servers and they had to change a hard disk and now on the most of our sites we can read only:
"The web page that you have requested is currently unavailable due to a temporary problem"

How long does google accept these page without updating their cache or without kicking the sites out of the serps?

Some days or weeks?

Thanks for your support.