iPhone OS 4 Event This April 8th! Posted on April 6, 2010 by Andrew A Quick Update: Apple just announced an iPhone OS 4 Event within 3 days from now, this Thursday on April 8th. The event is called “Get a sneak peak into the future of iPhone OS” and will start at 10AM. We will keep you informed. Related Andrew A Computer Science Student turned writer with my first gen iPhone. I write on my 13" MacBook Pro Retina and iPad Air Cellular. Black iPhone 5S is my sidekick.