Place the ham in a large slow cooker. Whisk the cider with brown sugar, bourbon, honey, and mustard. Slowly pour over the ham, then scatter thyme into the slow cooker.
Cook, on HIGH for 4 hours or on LOW for 8 hours, until very tender. Remove ham to rest on a cutting board.
Pass the remaining cooking liquid through a fine-mesh sieve into a saucepan. Simmer for 10 minutes or until slightly reduced.
Cut the ham into chunks or slices. Brush the cut pieces with the cooking liquid before arranging on a platter.