This alone would be a big help. In 1999, the government should set aside a good chunk of money in cash to be available in Jan, 2000. The Treasury should be directed to print lots of paper money. Driving restricted for the first day or so. A special one week bank holiday should be observed All gas stations closed.
Every generator is required to be tested in the week before the changeover.
All military equipment to be on triple-safe, available for use in emergencies only. FEMA should work with all state and local governments to prepare plans that assume that NO computer or telephone support will be available All heavy industrial equipment to be shut down for the day. All electrical grid operations to be un-automated A moratorium on all debt collections for the first two months and generous aid available. And you get the idea. Maybe there are some others on this NG that would like to contribute to a disaster plan.