[TUHS] Were cron and at done at the same time? Or one before the other?

This pair of commands exemplifies a weakness in the way Unix evolved. Although it was the product of a shared vision, It was not a product-oriented project. Unix commands work well together, but they don't necessarily work alike. It would be nice if identifiable families of commands had similar user interfaces. However, cron and at were written by different individuals, apparently with somewhat different tastes. Unix folks were close colleagues, but had no organized design committee. Time specs in cron and at are markedly different. A more consequential example is data-field specs (or lack thereof) in sort, join, cut, comm and uniq. The various specs were recognized as "wildly incongruent" in a BUG remak. However there was no impetus for unification. To paraphrase John Cocke (speaking about Fortran): one must understand that Unix commands are not a logical language. They are a natural language--in the sense that they developed by organic evolution, not "intelligent design". Doug