Select
     Cast(-53690 As DateTime) As 'Erstes Datum'
     , Cast(2958463.999999999 As DateTime) As 'Letztes Datum'

Erstes Datum              Letztes Datum             
------------------------- ------------------------- 
1753-01-01 00:00:00.000   9999-12-31 23:59:59.997  

(1 row(s) affected)