Prophet Forecasting

Overview

Prophet (Meta) decomposes time series into trend + seasonality + holidays + error. Uses an additive (or multiplicative) model fitted with Stan. Handles missing data, outliers, and holiday effects natively. Designed for business time series at daily/weekly granularity.

When to Use

Trigger conditions:

• Forecasting business metrics (sales, traffic, engagement) at daily/weekly frequency
• Data with strong seasonal patterns and known holiday effects
• Need quick, reasonable forecasts without deep time series expertise

When NOT to use:

• For high-frequency data (sub-hourly) — Prophet is designed for daily+
• When you need causal/explanatory models (Prophet is descriptive)
• For very short time series (< 2 seasonal cycles)

Algorithm