BTA Charts
ChartsIntensity & Density

Calendar Heatmap

A GitHub-style calendar grid where each cell represents a day, colored by a numeric value. Years are laid out as horizontal rows of weekly columns. Ideal for tracking daily activity, contributions, temperature, or any metric that varies day by day.

Examples

When to Use

  • Tracking daily activity patterns over a year (commits, workouts, sales)
  • Identifying seasonal or weekly patterns in time-series data
  • Visualizing streaks and gaps in daily metrics
  • Comparing activity levels across different time periods

Data Roles

Loading data roles...

Settings

Color & Appearance

Color Scheme

dropdown

Sequential color gradient from low to high values.

Default: greens

Calendar

Cell Size

dropdown

Size of each day cell: small, medium, or large.

Default: medium

Show Month Labels

boolean

Display abbreviated month names above the calendar grid.

Default: true

Week Starts On

dropdown

First day of the week: Sunday or Monday.

Default: sunday

Gradient Colors

Min Color

color

Color for the lowest values in the gradient.

Default: #f7fcf5

Max Color

color

Color for the highest values in the gradient.

Default: #006d2c

Common settings like Tooltip and Small Multiples configuration are covered in Shared Concepts.

Tips & Best Practices

  • Use a sequential scheme like "greens" or "blues" for intuitive low-to-high intensity reading
  • The calendar automatically groups dates by year -- each year gets its own row
  • Set "Week Starts On" to Monday if your audience uses ISO week numbering

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