Age spreads of the clusters (t_{90 − 10}) as the function of the cluster initial mass. The data with errorbars present the median age spreads of the [0, 20), [20, 40), [40, 60), [60, 80), [80, 100] cluster initial mass percentile bins, and the vertical errorbars show the 16 and 84 percentiles of the age spreads in each bin. More massive clusters exhibit larger age spreads, suggesting that the final mass of the cluster is influenced by the duration of star formation within the cloud when there is no disruptive stellar feedback.