Nested Hierarchy to Calculated Date - sql-server

Question

I am trying to convert an nested hierarchy from a currency holiday table to select the specific date occurrence for 2022.
Sample source table for explanation:
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| hol_ccy | holiday | date_type | hol_dt | hol_day_no | calloc_id | base_hol_id |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Good Friday | Date | 2022-04-15 00:00:00.000 | 0 | 9169 | NULL |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Easter Monday | Ordinal Based | 1899-12-30 00:00:00.000 | 3 | 9188 | 9169 |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Easter | Ordinal Based | 1899-12-30 00:00:00.000 | 2 | 9189 | 9169 |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Ascension | Ordinal Based | 1899-12-30 00:00:00.000 | 39 | 9190 | 9189 |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Whit Monday | Ordinal Based | 1899-12-30 00:00:00.000 | 50 | 9191 | 9189 |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
Desired Output:
CCY HOLIDAY DATE
CHF Good Friday 2022-04-15 00:00:00.000
CHF Easter Monday 2022-04-18 00:00:00.000
CHF Easter 2022-04-17 00:00:00.000
CHF Ascension 2022-05-26 00:00:00.000
CHF Whit Monday 2022-06-06 00:00:00.000
Row 1 is a given fact entered into the database for each year. Given as date_type: date
Rows 2 & 3 are based on Row 1. Each adding the value of hol_day_no to row 1's hol_dt (date). This relationship is described in calloc_id and base_hol_id columns
Rows 4 & 5 are based on Row 3.
I cant figure out how to treat the nesting of the ordinal based date types in SQL.
Any pointers would be appreciated.

Answer 1

It looks like a pretty simple recursive CTE is needed. You just need to add the child row's day number to the parent row's date.
WITH cte AS (
SELECT
t.hol_ccy,
t.holiday,
t.hol_dt,
t.calloc_id
FROM YourTable t
WHERE t.base_hol_id IS NULL
UNION ALL
SELECT
t.hol_ccy,
t.holiday,
DATEADD(day, t.hol_day_no, cte.hol_dt),
t.calloc_id
FROM YourTable t
JOIN cte ON cte.calloc_id = t.base_hol_id
)
SELECT
t.hol_ccy,
t.holiday,
t.hol_dt
FROM cte t;
db<>fiddle