FORMAT-DECODED-TIME formats a string containing decoded time
expressed in a humanly-readable manner. The destination is any
destination which can be accepted by the FORMAT function. The
timezone keyword is an integer specifying hours west of Greenwich.
The style keyword can be :SHORT (numeric date), :LONG (months and
weekdays expressed as words), or :ABBREVIATED (like :LONG but words are
abbreviated). The keyword DATE-FIRST, if NIL, will cause the time
to be printed first instead of the date (the default). The PRINT-
keywords, if nil, inhibit the printing of certain semi-obvious
parts of the string.