Environmental Permit Expiry Alert SQL Query Generator

SELECT permit_no AS permit_no,
       permit_type AS permit_type,
       site_code AS site,
       expiry_date AS expires_on,
       DATEDIFF(day, CAST(GETDATE() AS date), expiry_date) AS days_left,
       DATEADD(day, -renewal_lead_days, expiry_date) AS renewal_must_file_by,
       owner_email AS owner_email
FROM env_permit
WHERE expiry_date <= DATEADD(day, 120, CAST(GETDATE() AS date))
ORDER BY expiry_date;

SELECT permit_no AS permit_no,
       permit_type AS permit_type,
       site_code AS site,
       expiry_date AS expires_on,
       (expiry_date - CURRENT_DATE) AS days_left,
       (expiry_date - renewal_lead_days) AS renewal_must_file_by,
       owner_email AS owner_email
FROM env_permit
WHERE expiry_date <= CURRENT_DATE + 120
ORDER BY expiry_date;

-- Works in PostgreSQL. In SQL Server replace the date math with DATEADD as above.
SELECT permit_no, permit_type, expiry_date
FROM env_permit
WHERE (expiry_date - renewal_lead_days) < CURRENT_DATE
  AND expiry_date >= CURRENT_DATE
ORDER BY expiry_date;