This depends on your TTL (time to live) setting in your DNS record.

This setting varies by nameserver and you can view the TTL by looking up the SOA record for your domain. http://centralops.net/co/ offers a good tool for this.

TTL is listed in seconds so divide by 60 to get the minutes then divide again by 60 to get the number of hours.

Our default TTL is one day. That means any changes or modifications to your domain name will take one day to propagate throughout the entire internet. You can adjust your TTL if you plan on making changes quite often. If your lower to your TTL, it will put an increased load on the nameservers and could potentially increase the response time to end customers.

For example, if someone on the aol.com network were to view your website, AOL DNS resolvers would cache your domain name information for the term of the TTL and all future AOL users would use the local cached information for faster performance. If you lower your TTL to 5 minutes, your domain name information would propagate faster - but there would be little caching of your domain name information and DNS resolution would occur every five minutes making resolution a little longer. There is a performance/reward trade off for TTL settings.

Higher the setting - higher DNS performance due to local ISP caching

Lower the setting - lower DNS performance due to increased name resolution