As a simplified example:
(memory) [2023-07-01] My daughter is 10
(memory) [2024-05-30] My daughter turned 11 today!
System prompt: Today is 2025-08-21
User prompt: How old is my daughter?
The vector DB does the work of fetching the daughter-age-related memories, your system decides (perhaps with another LLM) if the question needs time-based sorting or something else.