csvgrab - need to change date in posts

I am creating a web store using a datafeed from a merchant. With csvgrab, I transferred over 17000 items into the database. Unfortunately I stupidly set the stagger to 3600 seconds per record. So EE posts one new record per hour. With so many items it will take until 2009 to complete all the records!

I tried running csvgrab again with a 1 second stagger time but it does not seem to readjust the stagger time. Please advise how I can change the entry date for all my records to a single time so they can all be input at once.

Thanks

Mod Edit: Moved to the Plugins forum