While the cutoff for training can be around a year or so, they can access the web now so it should have been able to know this, it can summarize, connect, extrapolate, etc any info it can access on the web. While still capable of hallucination, less and less over time, but OP probably unknowingly or knowingly gave it a constraint when they fed it the info, it might have taken that as only using said info, and existing training data, measuring new info against training and rendering false. Mentioning something like what is a major event that happened last week, it will give a summary of that with highlights then sources. Then you can ask it anything about those. Anything that it could do with its training data, it can do with this temporary data, then a new chat the web’s data is not preserved when you ask it a follow up. It initially uses training data only until you mention a recent time indication in your prompt, then it has the only choice of using the web, as long as it isn’t requested not to. There are some other phrases that may prompt a web search, it uses its best ‘judgement’ for this.