Like most types of web hosting now, you are able to get 24 hour support when you opt for managed hosting. This means that no matter what day of the week or what time of the day you are up and checking out your website, you can phone, e-mail or live chat and be certain that you are going to get a response and have the problem fixed in no time.
This is extremely beneficial if you find that your website is down at 2am on a Saturday or Sunday morning. You need to remember that while you should be in bed, there are people all around the world that could see your website, or at least try to see your website.
As soon as you find that it is down, you should aim to get it back up and running within minutes so that you do not lose out on potential business. Your hosting company may not initially be aware of the problem so you will need to inform them so that they can do something to help you.