DNS update : Shaw vs. Telus

I changed my site’s DNS setting through 1and1 yesterday. The site can not be reached about 1 day average. The same situation I met almost two or three times a year.
I browse my site properly last night. I use Shaw Cable at home. They always update their DNS server very quickly.
The problem is Telus. I have nothing to do in my office this morning, which use Telus.
Telus’s DNS server still has my old IP address.
How to access my site?
I changed TCP/IP setting in my workstation.
Firstly, get the IP address of DNS server from my home computer.
Click Run, enter command to get the command prompt.
Enter ipconfig/all, records the IP address of DNS Servers.
Secondly, go to my office PC, in TCP/IP properties, enter the IP address I got above into the preferred DNS server.
Now I can use the Shaw’s DNS server through Telus Internet connection.

I am not sure, when Telus will refresh its DNS server.
Basicly I think Shaw is better then Telus.