>I have a minutes numeric field mytable.minutes
>
>But when I have a great large of minutes as 720 or more I would like to store them
>in a datetime field
>
>Replace mytable.datetime with mytable.minutes * 60 + mytable.minutes
>
>But I have to reset mytable.datetime field to zero before sum
>
>How can I do it ?
>
>Moises

You need to use some base date here, you can not set datetime to 0.

Pick up some date, say, 1/1/1900 (to be in the same boat as SQL Server) and use it as a base.