How long do you have to wait to hunt after buying you license and tag

There is no waiting period in Idaho.  Once you buy your license and tag, you can immediately go hunting (provided the season is open).   Years ago (30+) there was a waiting period of 24 hours to dissuade people from illegally killing a deer or elk and then going to the closest vendor and buying a license and/or tag.  With current forensic technology and real-time uploading of license purchasing information, we can easily prove a case when someone tries this unethical hunting trick.