In English, not SQL, what are you trying to accomplish here? Have you taken a look at DATEADD(hour, DateField)? To strip the time portion of a datetime field, use DATEADD(day, 0, DATEDIFF(day, 0, DateField)) since it requires no lookup to syslanguages to find the localization string for CONVERT(varchar, DateField, 112). Also, use the BETWEEN clause. Demonstrated techniques below...:

WHERE 

--...statements here...

AND

(

dbo.mainb.tarihb BETWEEN 

DATEADD(hour, 1, DATEADD(day, 0, DATEDIFF(day, 0, GETDATE())))

AND

DATEADD(hour, -1, DATEADD(day, 31, DATEADD(day, 0, DATEDIFF(day, 0, GETDATE()))))

OR

--...convert the rest like above...