Change format date parameter ordere

The following discussion from !12 (merged) should be addressed:

• @informatimago started a discussion:

  Just a comment: if format-date-time accepted the parameters in the same order as decode-universal-time produces them, we could just call directly: (multiple-value-call (function format-date-time) (decode-universal-time ...))) It's one-shot, so it doesn't matter here. (format-date-time could be inlined).