Originally Posted by
orca15
I've had good luck canceling anytime the day prior...I guess you could always argue that since you are canceling, any old time is at least 24 hours prior to "arrival".
I think prior to 6PM would be a good rule of thumb, barring better info.
I would not rely on this. Rely on the specific language of the confirmation. It is generally 24 hours to the posted check-in time, but often is a specififed local time. Remember to factor in time differences because it's almost local time for the property.