Исходное число - это интервал, выраженный в количестве дней.Следующее немного уродливо, но может помочь показать, что происходит:
SELECT days,
hours,
minutes,
seconds,
TO_CHAR(days, 'FM9') || ' ' ||
TO_CHAR(day_hours, 'FM09') || ':' ||
TO_CHAR(minutes, 'FM09') || ':' ||
TO_CHAR(seconds, 'FM09') AS interval_string,
TO_DSINTERVAL(TO_CHAR(days, 'FM9') || ' ' ||
TO_CHAR(day_hours, 'FM09') || ':' ||
TO_CHAR(minutes, 'FM09') || ':' ||
TO_CHAR(seconds, 'FM09')) actual_interval
FROM (SELECT float_val,
days, hours, minutes,
hours - (days * 24) AS day_hours,
ROUND((((decimal_hours - hours) * 60) - trunc((decimal_hours - hours) * 60)) * 60) AS seconds
FROM (SELECT float_val,
trunc(hours / 24) AS days,
decimal_hours,
hours,
(decimal_hours - hours) * 60 AS decimal_minutes,
trunc((decimal_hours - hours) * 60) AS minutes
FROM (SELECT float_val,
float_val * 24 AS decimal_hours,
TRUNC(float_val* 24) AS hours
FROM (SELECT 1.33408564814814 AS float_val FROM dual))));
Поделитесь и наслаждайтесь.