I am trying to figure out how to alter a column's data type from a date
to a timestamp without time zone. Is this possible or do I have to
drop the column and then add it back with the correct data type? Below
is the table:

rpdb3=# \d reports
Table "public.reports"
Column | Type | Modifiers
----------------------+--------------+-----------
day | date | not null
hbt | character(2) | not null
chain | character(2) | not null
pass | integer | not null

Indexes:
"reports_pkey" primary key, btree ("day", hbt, chain)


I need the table to be:

rpdb3=# \d reports
Table "public.reports"
Column | Type | Modifiers
----------------------+--------------+-----------
day | timestamp without time zone | not null
hbt | character(2) | not null
chain | character(2) | not null
pass | integer | not null

Indexes:
"reports_pkey" primary key, btree ("day", hbt, chain)