Forecasting Time Series Data with Prophet - Second Edition

5

Working with Seasonality

One quality that sets time series apart from other datasets is that very often – but not always – the data has a certain rhythm to it. That rhythm may be yearly, possibly due to the Earth’s rotation around the Sun, or daily, if rooted in the Earth’s rotation around its axis. The tidal cycle follows the Moon’s rotation around the Earth.

Traffic congestion follows the human activity cycle throughout the day and the 5-day workweek, followed by the 2-day weekend; financial activity follows the quarterly business cycle. Your own body follows cycles due to your heartbeat, breathing rate, and circadian rhythm. On very small physical and very short temporal scales, the vibration of atoms is a cause of periodicity in data. ...