Having more context, but leaving open an inability to effectively focus on the latest task is the real problem.
I know there classes of problems that LLMs can't natively handle (like doing math, even simple addition... or spatial reasoning, I would assume time's in there too). There are ways they can hack around this, like writing code that performs the math.
But how would you do that for chronological reasoning? Because that would help with compacting context to know what to remember and what not.
In theory you could attach metadata (with timestamps) to these turns, or include the timestamp in the text.
It does not affect much, other than giving the possibility for the model to make some inferences (eg. that previous message was on a different date, so its "today" is not the same "today" as in the latest message).
To chronologically fade away the importance of a conversation turn, you would need to either add more metadata (weak), progressively compact old turns (unreliable) or post-train a model to favor more recent areas of the context.