24 hours is the only fair way - if it is 6 hours....and someone posts their pick at 10PM, and then ext person has gone to bed.....they only have until 4AM to get their pick in. I highly doubt many (if any) picks will go the full 24 hours.
This was posted at 5:27pm I'm not aware of the different times zones for each but 24hrs is about over.
His sig does say the bears, so just give them to him