It entirely depends on the context and date of the hoard. Most of the early hoards (10th-12th centuries) won't contain coins from more than, let's say, 20 years apart due to the reminting of old coins into new types every few years. However, when we get to later periods (15th-17th centuries) we see coins from across vast periods being contained within them, e.g. the Hartford Hoard that had 1,108 silver groats from the reigns of Edward IV, Henry VI, Richard III and Henry VII, and double patards of Charles the Bold.