Problems in DATE equality

Something went wrong in last times, because I can't do something very usual, like DATE equalitity tests.

I have got a DATE field in a table : when I try to select with an EQUAL condition in the WHERE on this field, like this : SELECT * from TABLE where DATE_FIELD = TO_DATE('16051997','DDMMYYYY') I don't get any records !

Note that the SELECT returns the right answer if I put it like this : SELECT * from TABLE where DATE_FIELD BETWEEN   TO_DATE('15051997','DDMMYYYY') AND TO_DATE('17051997','DDMMYYYY') so it seems that the problem is with equality only.

I have tried to select with the time too, like this : SELECT * from TABLE where DATE_FIELD =
TO_DATE('16051997045715','DDMMYYYYHHMISS) but also this didn't succeed.

Could someone give an explanation ?
Thanks Received on Mon May 19 1997 - 00:00:00 CDT