Auntie Dora is a great cook. Her fond nephew gave her an XT and dot matrix printer for her birthday so that she can type out her recipes and swap them at the Ladies League. Auntie Dora has never entered a date onto her system ever. She doesnt even use directories.
When she switches her system on, the date defaults to 1980. Every file she has ever created has a date of 1980. She uses filenames like "strudel" and "cupcakes" and is as happy as a sandlark. When the fond nephew suggests that she types in the date at startup time, she looks at him strangely. Auntie Dora can use her system until the end of time.
For our purposes, let us define Auntie Dora as a "Class 0 Y2k object".