Hàm random khoảng thời gian trong sqlserver

Question

SELECT CAST( DateAdd(d, ROUND(DateDiff(d, '1970-01-01', '2021-12-31') * RAND(CHECKSUM(NEWID())), 0),
      DATEADD(second,CHECKSUM(NEWID())%48000, '1970-01-01')) AS DATE)