The Compare Interval Time routine compares two binary timestamps
    and returns a flag indicating that the first time is greater
    than, less than, equal to, or overlapping with the second time.
    Two times overlap if the intervals (time - inaccuracy, time +
    inaccuracy) of the two times intersect.

    The input binary timestamps express two absolute or two relative
    times. Do not compare relative binary timestamps and binary
    timestamps. If you do, no meaningful results and no errors are
    returned.

    This routine does a temporal ordering of the time intervals.

    utc1 is utc_lessThan utc2 iff
            utc1.time + utc1.inacc < utc2.time - utc2.inacc

    utc1 is utc_greaterThan utc2 iff
            utc1.time - utc1.inacc > utc2.time + utc2.inacc

    utc1 utc_equalTo utc2 iff
            utc1.time == utc2.time and
            utc1.inacc == 0 and
            utc2.inacc == 0

    utc1 is utc_indeterminate with respect to utc2 if the intervals
    overlap.