14.2 Seasonality

Seasonality captures effects that occur with specific frequency. It can be driven by many factors.

• Short-term regular wave-like patterns

• Observed within 1 year

• Often monthly or quarterly

• Naturally occurring events, such as weather fluctuations caused by time of year

• Business or administrative procedures, such as start and end of a school year

• Social or cultural behavior, such as holidays or religious observances

• Fluctuations due to calendar events, such as the number of Mondays per month for trading or holidays that shift from year to year (Easter, Chinese New Year)