Does filing a duplicate provisional patent negate the original's filing date?

[PPage]

I filed a provisional patent app about a year ago. Seven months later I refiled the exact same provisional. Does the second filing delete or get rid of my original filing date? Do I now only have the second filing to rely on as a priority date? Or is the original first provisional priority date still valid?

[Brad]

Although the second one does not negate the first (i.e. you can have two co-pending provisionals), your first provisional will expire after 12 months.   If its been longer than 12 months since you file the first provisional you only have one pending provisional which is the more recent one your filed.