Encode HIGH, LOW, MICRO, and PICO into a time value of type TYPE.
Type 0 is the cons cell (HIGH . LOW), type 1 is the list (HIGH LOW),
type 2 is (HIGH LOW MICRO), and type 3 is (HIGH LOW MICRO PICO).
For backward compatibility, if only four arguments are given,
it is assumed that PICO was omitted and should be treated as zero.