A timescale is a measure of time, usually referring to periods or intervals of time that are used as reference points for historical or geological events. It can also refer to the rate at which something changes over time, such as the pace of technological advancements or the speed of natural processes like erosion. In general usage, a timescale refers to any system of measurement or organization of time, whether it be based on years, centuries, millennia, or other units of measure.