Rationale behind BCH hardfork date

I was wondering about the reasoning for selecting Bitcoin Cash's hardfork date. AFAIK the fork (August 1, 2017) was in direct response to SegWit (August 24, 2017), which raises the question of why it was decided to activate 3 weeks earlier than SegWit. Logically I would think that the fork would be activated at the same blockheight as SegWit (effectively creating a sudden split in the chain), but this is not what happened. Is there any reasoning behind this, or was it an arbitrary decision?

Just curious.