Update multiple Postgres timestamps - django

Question

I am attempting to update timestamps for 100s of objects in Postgres 12 using the following query:
UPDATE foo_bar AS c SET
created_at = c2.created_at
FROM (VALUES
(101, '2021-09-27 14:54:00.0+00'),
(153, '2021-06-02 14:54:00.0+00')
) as c2(id, created_at)
WHERE c.id = c2.id;
Where created_at represents a dateTimeField:
created_at = models.DateTimeField(auto_now_add=True)
I am receiving the following error:
ERROR: column "created_at" is of type timestamp with time zone but expression is of type text
I have tried many variations of the created_at values to no avail. Any idea why this is not working?

Answer 1

Thank you to #a_horse_with_no_name for the answer. I had to cast the values as timestamps with timezones as shown below:
UPDATE foo_bar AS c SET
created_at = c2.created_at
FROM (VALUES
(101, '2021-09-27 14:54:00.0+00::timestamptz'),
(153, '2021-06-02 14:54:00.0+00::timestamptz')
) as c2(id, created_at)
WHERE c.id = c2.id;
Postgres docs explaining how casting works (link):
A cast specifies how to perform a conversion between two data types
By default, a cast can be invoked only by an explicit cast request, that is an explicit CAST(x AS typename) or x::typename construct.
Postgres docs explaining timestamptz (link):
timestamptz is accepted as an abbreviation for timestamp with time zone