Currently, if the i field of the global OpTime on a server increments past signed int max, we abort the process:

     if (val.getInc() & 0x80000000) {
            mongo::warning() << "clock skew detected  prev: " << val.getSecs()
                             << " now: " << (unsigned) time(0) << std::endl;
            return true;
        }

Instead, we could handle this by incrementing the "secs" field by one and resetting the "inc" field back to 1. (The code resets the inc field back to 1 instead of 0 in the normal case, for some reason.)