Round date to 10 minutes interval

Question

I have a DATE column that I want to round to the next-lower 10 minute interval in a query (see example below).

I managed to do it by truncating the seconds

Answer 1

Another method,

select my_date - mod( (my_date-trunc(my_date))*24*60, 10)/24/60
from (
  select sysdate my_date from dual
);

An alternative that might be quicker as it removes the call to trunc.

select my_date - mod( (my_date-to_date('1970', 'yyyy'))*24*60, 10)/24/60
from (
  select sysdate my_date from dual
);