When you register a new domain, the nameservers are changed. In other words, changes are made in the Domain Name System (DNS), and you can expect these changes to propagate within 24 hours.

• TTL (Time to Live) Settings: TTL is the time it takes servers to cache the new information for your DNS records. Since it is possible for you to set the TTL for each DNS record inside the zone file of your domain name, you may decide to set it at, say, two hours. This indicates that whenever there are changes in your DNS records, servers will store the information locally for two hours before retrieving the updated information from your designated/authoritative nameserver. You can, through this approach, increase the speed of propagation of your DNS changes. Using shorter TTL may help you speed up the propagation, but the downside of this method is that it could lead to overloading of the servers, if you have many changes that will eventually bombard the server with many queries at the same time. In this case, your server’s processing speed will become slower due to overloading.
• The efficiency of your ISP (Internet Service Provider): Normally, your ISP will cache or store DNS records locally instead of retrieving fresh or new data from your DNS server. This is done to slow down the traffic and increase the internet browsing speed. So, it may take your ISP two to three days to cache or update DNS records by ignoring TTL setting altogether. But this approach drastically reduces the propagation time, since you will have to wait for the next 2 to 3 days to update the changes in your DNS records.
• How about your domain name’s registry? Most domain names’ registries attempt to make DNS records’ updates as quickly as possible. VeriSign, for example, updates zones for .com domain names every three minutes. If you are using GoDaddy, the changes in your domain name’s nameservers are promptly forwarded to the registries within minutes, and your new authoritative nameserver (NS) records are published to their root zones. However, some registries are wary of doing quick updating of customers’ DNs records because they worry that such an action will cause their root nameservers to be overused. What they usually do in this circumstance is to set up a high TTL of up to 48 hours or more to refresh clients’ DNS records. Technically, the recursive nameservers are not expected to cache the root NS records, but some Internet Service Providers cache the data anyway, and this eventually slows down the nameserver propagation time.