The Movie Timeline - of all the movie timelines on all the net, you walked into this one
Splice - timeline
Saturday 14th March: Dren kills a cat. Elsa cuts off her stinger.
Sunday 15th March: Clive has sex with Dren. Dren later becomes male, kills Barlow, Gavin, and Clive, and rapes Elsa, possibly impregnating her in the process.