Try a record selection formula (Report->Edit Selection Formula->Record) containing:
(
{table.datetime} >= cdatetime(year(currentdate-1),month(currentdate-1),day(currentdate-1),15,0,0)
and
{table.datetime} <= cdatetime(year(currentdate-1),month(currentdate-1),day(currentdate-1),23,59,59)
)
and
(
{table.datetime} >= cdatetime(year(currentdate),month(currentdate),day(currentdate),0,0,0)
and
{table.datetime} <= cdatetime(year(currentdate),month(currentdate),day(currentdate),6,0,0)
)
-k