[Eikinskjaldi]

OK, well lets assume you have start_date and end_date in sql format, for example

start_date = '2007-08-07'

the query would then be

update post set threadid=new_thread_id where threadid=old_thread_id
and dateline between (unix_timestamp(start_date), unix_timestamp(end_date))

Of course, given that the thread table has all sorts of co-dependencies related to lastpost and first post, I have absolutely no idea how the posts will view in the new thread.

If I was going to do this, and first I'd have to wrap my head around the concept of a thread needing to be of manageable size, I'd be doing it in code with the data managers.

EDIT: I am going off 3.5+ database structure. I have no idea if 3.0.x has the same tables and or fields.