What will happen to Julia's DateTime type

Do we need to redefine Julias DateTime type, now that UTC will not follow UT1 anymore? I guess this will be very tricky to solve. When UTC and UT are beginning to diverge in the future, we probably do not want our default DateTime to be in UT. Of course there is probably no need for immediate action, since it will take decades for both to diverge significantly, but I would be interested if there are already ideas out how to solve potential issues.