Business never stands still, and neither does business data. Every data set is just a snapshot of a business. Each feature in data has a time frame before a snapshot date. Even within a time frame, some data still has temporal dynamics. We'll detail this point using three examples. The first is about historical prices of stock market; the third introduces a paper which shows a subtle temporal nature in beer reviews. The two are described briefly. The second is about the effect of cutoff dates on the target feature in survival analysis.
