Comment by hn_throwaway_99

Just a minor correction, but I think it's important because some comments here seem to be giving bad information, but on OpenAI's model site it says that the knowledge cutoff for gpt-5 is Sept 30, 2024, https://platform.openai.com/docs/models/compare, which is later than the June 01, 2024 date of GPT-4.1.

Now I don't know if this means that OpenAI was able to add that 3 months of data to earlier models by tuning or if it was a "from scratch" pre-training run, but it has to be a substantial difference in the models.