The AI Models Index keeps tabs on premium model releases from 15 top labs since...

https://technivorz.com/how-long-does-google-take-between-announcing-and-shipping-a-model/

The AI Models Index keeps tabs on premium model releases from 15 top labs since 2023, with verified dates and blind-vote accuracy checks. Updated every two weeks, it shows a steady pace—like GPT-5.2 rolling out just 4.5 days after GPT-5