ORA-01427: single-row subquery returns more than one row

Hi,

I have a report to create then there's a little problem I can't solve because the column(date) I generate has a different value and used it in a subquery. Now, my question is can I used a format so that I can manage to edit the value of the column. Please see the table below for reference,

My column(date) contains

date_columns
2019-06-20T11:09:15.674+00:00 2019-06-20T11:09:15.674+00:00 2019-06-20T11:09:15.674+00:00 2019-06-20T11:09:15.673+00:00

Now, my problem is it returned me ORA-01427: single-row subquery returns more than one row becaue of that '2019-06-20T11:09:15.673+00:00', now my question can I do a format to make it