Use the proper datetype date to compare dates.

SELECT TO_DATE('07-Feb-2015','DD-MON-RRRR'),sysdate

from dual

where TO_DATE('07-Feb-2015','DD-MON-RRRR')<sysdate;

OR

SELECT TO_DATE('07-Feb-2015','DD-MON-RRRR'),sysdate

from dual

where MYDATE<TRUNC(TO_DATE('07-Feb-2015 15:00:00','DD-MON-RRRR HH24:MI:SS'));

*if you use date(time)parameters the TO_DATE isn't necessary

To get 7 februari

SELECT ...

FROM ...

WHERE MYDATE>=TRUNC(TO_DATE('07-Feb-2015','DD-MON-RRRR'))

AND MYDATE<TRUNC(TO_DATE('07-Feb-2015','DD-MON-RRRR'))+1