SELECT [day] = Datediff(dd, st, et),
[hour] = Datediff(hh, st, et) % 24,
[minute] = Datediff(n, st, et) % 60
FROM (SELECT st = CONVERT(DATETIME, '02-21-2012 00:00'),
et = CONVERT(DATETIME, '02-22-2012 01:01')) tbl
Мне просто не нравится многократно вводить '02 -21-2012 00:00 '..