select *
from gkda
where
convert(varchar(5),birthday,110)
in ((convert(varchar(5),getdate()+1,110),
(convert(varchar(5),getdate()+2,110),
(convert(varchar(5),getdate()+3,110)
)
select * from gkda where Month(getdate())=Month(字段)
and Day(getdate())=Day(字段)