Or the other way around

😎

SELECT

T1.ID

,T2.XDATE

FROM dbo.TABLE1 T1

RIGHT OUTER JOIN dbo.TABLE2 T2

ON T1.XDATE = T2.XDATE;

Output

ID XDATE

----------- ----------

100 2015-05-05

222 2015-05-05

100 2015-05-06

222 2015-05-06

100 2015-05-07

NULL 2015-05-08