  Variability in the brightness of Young Stellar Objects (YSOs) is a common
phenomenon that can be caused by changes in various factors, including
accretion, extinction, disk morphology, interactions between the disk and the
stellar photosphere, and the rotation of hot or cold magnetic spots on the
stellar photosphere. Analyzing the variability on different timescales gives
insight into the mechanisms driving the brightness changes in YSOs. We
investigate the variability of YSOs on both long and short timescales using two
mid-infrared datasets: the NEOWISE 7.5-year W2 (4.6$\mu$m) data and the YSOVAR
40-day Spitzer/IRAC2 (4.5$\mu$m) data, respectively. We classify the
variability types in each timescale following Park et al (2021). We find a
higher detection rate of variable sources in the short-term (77.6%) compared to
the long-term (43.0%) due to the higher sensitivity of the Spitzer
observations. In addition, the higher cadence of the YSOVAR data results in the
weeks-long short-term variability being mostly secular, while the years-long
long-term variability explored with the coarsely sampled NEOWISE data is mostly
stochastic. By cross-matching the two catalogs, we statistically analyze the
variability types exhibited by YSOs across both timescales. The long-term
variability amplitude is mostly three times (up to ten times) greater than the
short-term variability. Furthermore, we evaluate variability on very short (1-2
days) timescales and recover a trend of the increasing amplitude of variability
as the timescales increase. By comprehensively analyzing the variability of
YSOs over various timescales, we contribute to a deeper understanding of the
underlying mechanisms driving their variability.
