Line Charts, Trend Lines & Date Hierarchies

Reading Time: 8 Mins | Level: Beginner to Advanced

1. Automatic Date Hierarchies

When a Date field is dragged onto a shelf in Tableau, it automatically creates an interactive hierarchy: $$ ext{Year} o ext{Quarter} o ext{Month} o ext{Day}$$ Clicking the plus sign ($+$) on the pill expands the hierarchy!

2. Date Parts (Discrete) vs Date Values (Continuous)

Right-clicking a date pill reveals two distinct sections of dates:

• Top Section (Date Part - Blue Discrete): Compares cyclical patterns across years (e.g., all Januarys across 2024, 2025, 2026 combined into one bucket).
• Bottom Section (Date Value - Green Continuous): Plots a chronological timeline from historical past to future (e.g., Jan 2024 $ o$ Feb 2024 $ o$ Mar 2024).

3. Adding Statistical Trend Lines

• Open the Analytics Pane (next to the Data pane) $ o$ Drag Trend Line onto the canvas (Linear, Logarithmic, Exponential, Polynomial).