The phrase "multiple timescales" refers to different, separate periods or intervals of time that are happening at the same time or within a certain context. Full definition
The brain of any animal has to operate on multiple timescales at once. (simonsfoundation.org)
Our work in the lowly roundworm will shed light on how the nervous system processes information over multiple timescales with relevance for larger animals, including humans. (simonsfoundation.org)
Archer, D., Kheshgi, H. & Maier - Reimer, E. Multiple timescales for neutralization of fossil fuel CO2. (nature.com)