Convert Datetime of query otimize.

Hello All,

In following statement in SQL, Which one should I use and why. My intention to get the record between the date and with style 101.
Which is in following is right one. If I use first('A') then it's little bit slower than second 'B'. So Please suggest me asap.

A.

convert(datetime,convert (nvarchar,Cert_WarehouseDetails.IssuedDateX,101)) <= '3/29/2004')
and
(Cert_WarehouseDetails.IssuedDateX is NOT NULL AND
convert(datetime,Cert_WarehouseDetails.IssuedDateX ,101) <= '3/11/2004')
convert(datetime,convert(nvarchar,Cert_WarehouseDe tails.IssuedDateX,101)) <= '3/12/2004')

B
Instead that Can I use like below, as

(convert(datetime,Cert_WarehouseDetails.IssuedDate X,101) >= '1/1/2004') AND
(Cert_WarehouseDetails.IssuedDateX is NOT NULL AND
convert(datetime,Cert_WarehouseDetails.IssuedDateX ,101) <= '3/11/2004')

Please reply to me asap.

Regards,
M. J.

__________________Replace all occurrances of <= and >= along with the date specified with < original_date_plus_1 and > original_date_minus_1. This way you won't have to deal with CONVERT.|||Originally posted by rdjabarov
Replace all occurrances of <= and >= along with the date specified with < original_date_plus_1 and > original_date_minus_1. This way you won't have to deal with CONVERT.

Do I have to use 'nvarchar' while converting to datetime.