Entering a value greater than 0 will inject a cookie in the visitor's browser to tell our system the the visitor has arrived from a bypassed domain or IP address.
This will ensure they are not redirected again if they visit your website directly.
However you also have links in the Canadian website that goes to http://website.com
By adding the domain http://website.ca into the list of bypasses, if a Canadian visitor browsing on http://website.ca clicks on the link to http://website.com, they will not get forced redirected back to http://website.ca
Cookie time is entered in hours and there is no limit on the number of hours that can be entered.