As long as you keep the canned sauerkraut properly and continually refrigerated the canned sauerkraut will last up to 7 days which is a week.
So be sure to eat the canned sauerkraut within a week so that it won't go bad and after a week the canned sauerkraut is likely no good anymore and should be thrown out because it can make you sick.
If the canned sauerkraut is unopened then it can last for a year or more before going bad but it's best to eat the canned sauerkraut or any other canned foods before the use by date for the best freshness.
After you open the canned sauerkraut it's best to put it in a covered plastic container or plastic Ziploc bag to maximize the freshness and prevent it from absorbing any other food odors in the refrigerator.