150v2

WITH maxDate
AS
(
SELECT point, MAX(date) AS date
FROM Income
GROUP BY point
),
minDate
AS
(
SELECT point, MIN(date) AS date
FROM Income
GROUP BY point
),
lagLead
AS
(
SELECT point, LAG(date) OVER (ORDER BY date) AS lag, date, LEAD(DATE) OVER (ORDER BY date) AS lead
FROM Income
),
notNullLead
AS
(
SELECT ll.point, ll.date, lead
FROM lagLead ll
JOIN maxDate maD ON ll.point = maD.point AND ll.date = maD.date
WHERE ll.date != lead
),
notNullLag
AS
(
SELECT ll.point, ll.date, lag
FROM lagLead ll
JOIN minDate miD ON ll.point = miD.point AND ll.date = miD.date
WHERE ll.date != lag
),
AS
final
(
SELECT miD.point, lag, miD.date AS min_date, maD.date AS max_date, lead
FROM minDate miD
JOIN maxDate maD ON miD.point = maD.point
LEFT JOIN notNullLag nnla ON miD.point = nnla.point AND miD.date = nnla.date
LEFT JOIN notNullLead nnle ON maD.point = nnle.point AND maD.date = nnle.date
)