I am working for my clients site. He had asked this question that does ranking get lost if the google or other search engines do not find the site for 3 days... Does it impact SEO of site.
Yes, Google gives 24 hours relaxation time for your site; if you are working out on your site for more than 24 hours there is a chance that you can loose your ranking;so if site is not found 3 days rankings can get down.
But in my experience the ranking eventually returns when the site is put back online for a couple of weeks. Anyways I don't take any chance, and I leave a copy of the original site online as I work on the new version whenever it's possible..
it will not effect too much if you have strong point on position . once your site/blog is back online than it will hit his position in few latest updates again...
It depends on the crawling rate on your website by the Google crawlers. If within 3 days, Google crawlers come to your website and don't find your website, then you may lose rankings. And if they don't visit within this time period and you update your website, then there will be no impact.
If the site is only down for 3 days it won't make a big difference. But after a while Google and other search engines will start de-indexing your website. If it cannot be found.
i think it's not good idea to close the site for 3 days. You'd better do the maintenance in 24 hours only and fix the rest another day
It will affect your ranking for 1-2 weeks after its back up but google may eventually return your ranking if you have all the backlinks intact.