Hi.
Did you try putting Type=date in the fields.ini of the table with the grafted field?
Like this:
fields.ini in the /tables/tableA folder:
__sql__ = "
SELECT
A.*
, '2024-02-03' AS grafted_field
FROM
tableA A
"
[grafted_field]
Type=date
Without Type=date the field is rendered as '2024-02-03', while with Type=date it is rendered as '02/03/24' implying that the grafted field had been converted to a date and formatted consequently.