SQL to Get dates missing in a table for given date range

 WITH all_dates AS (

    SELECT DATE '2025-01-01' + LEVEL - 1 AS dt

    FROM dual

    CONNECT BY LEVEL <= (DATE '2026-01-01' - DATE '2025-01-01') + 1

),

existing_dates AS (

    SELECT TRUNC(creation_date) AS dt

    FROM  XXCUST.CUSTOM_TL -- your table name

    WHERE creation_date BETWEEN DATE '2025-01-01' AND DATE '2026-01-01'

)

SELECT a.dt AS missing_date

FROM all_dates a

LEFT JOIN existing_dates e

       ON a.dt = e.dt

WHERE e.dt IS NULL

ORDER BY a.dt;