If we were to set the date in our computers back a month, to say March 1st, would we be able to avoid the attack (temporarily)?
It might, but why bother? Only 3-6% of computers in the US are estimated to be infected. I'm not sure about Canada, but I expect that the rate is similar.
There is a very simple and fast way to know whether or not your computer is infected. Simply reboot into "safe mode". Conficker C prevents this, so if you can do it, you're fine.