Depending on what registrar you used, this could take anywhere from a few minutes to, more likely, 24 hours. The default global DNS update configuration is 24 hours to refresh, though some services might take as long as several days. Changes or additions made to DNS for domains registered with Superb should start working in 24 hours, on average.
The updates are generally applied to our DNS servers themselves nearly instantly, though other servers around the world only update their database records from their neighboring authoritative DNS servers once every 24 hours. Depending on the timing of your DNS change as compared to your Internet Service Provider’s update window, delays may vary and not all ISP’s adhere to the 24 hour default. Even if you can see the changes have taken effect, your clients or other visitors may not at the same time, depending on their connection.
If changing hosting or services, it is recommended when possible to schedule the startup and shutdown of services to overlap, so that DNS changes may be initiated while the old site is still live and as long as the new site is also live and waiting the changeover, there should be no loss of service while this change propagates globally.