@srol sorry. Time To Live. It tells DNS servers how long they can cache DNS records for. It should be one of your Route 53 settings. Frequently it is set to a day or more, so it can take a long time for everyone to find out about a server change. I’m not sure what Amazon defaults it to.

@edebill @srol
I wouldn't worry about it too much, unless it is a really busy server odds are not many people will have the current DNS answer cached. And usually the DNS servers that do the caching have a shorter maximum TTL.

In my experience around 4 hours is the longest you will usually wait for a domain to point to the new webserver.

Will you also change the email destination (MX-records)?