Calendar heat charts visualize patterns in temporal data by aggregating incidents into a calendar grid. Calendar grids can be configured to display temporal patterns across the months in a year or across the days in a week.
In a year view, each row in the calendar grid corresponds to a month, and each column corresponds to a day of the month.
In a week view, each row in the calendar grid corresponds to a day of the week, and each column corresponds to an hour of the day.
Each cell in the calendar heat chart corresponds to the specific calendar unit defined by the intersection of the row and column, and all incidents sharing those two dimensions will be aggregated into the same cell. For example, when aggregating a dataset spanning multiple years into a single year view, all incidents with the dimensions October and 22 will be aggregated into the same cell, regardless of year. Similarly, when aggregating a dataset spanning multiple weeks into a single week view, all incidents with the dimensions Wednesday and 12pm will be aggregated into the same cell, regardless of week number. This single calendar view reveals typical day-of-month or hour-of-day patterns found by summarizing many time spans into one calendar.
Example
The calendar heat chart below identifies patterns in car accidents based on the day of the week and time of day.
- Date—Date
- Calendar type—Week by day of week and hour of day
- Select aggregation—Count
Data
The Data tab 
configurations include the variables and color scheme used to create the calendar heat chart.
Variables
Calendar heat charts aggregate a Date field into a calendar grid. The calendar grid can be divided into one of two Calendar type options: Year by month and day of month or Week by day of week and hour of day.
Note:
The Date field must be of type Date.
Temporal data is displayed using the time zone in your computer's system settings.
By default, a calendar heat chart displays the count of records that took place in each temporal unit. Optionally, a numeric variable can be summarized by choosing a Numeric field variable and an Aggregation method. The aggregation method can be one of the following:
- Count
- Sum
- Mean
- Median
- Minimum
- Maximum
Note:
By default, February 29 is not included when drawing a calendar heat chart. To include February 29, enable Include leap day.
Color
Grid cells are symbolized using graduated colors that correspond to a count or summarized value taking place in each calendar unit. Method, Number of classes, and Color scheme are used to symbolize the grids. Method determines the classification and supports the following options: Natural breaks (Jenks), Equal intervals, and Quantiles. The default number of classes is 5.
You can change the color ramp on the chart by clicking the menu for Color scheme. You can filter the color ramps by categories like Dark, Blues, and Colorblind friendly. You can also flip the order of the colors in the color ramp.
You can change the color used to indicate null values using the color patch next to Null.
Format
The Format tab 
configurations are used to change the look of the chart by formatting text and symbol elements.
Chart formatting options include the following:
- Text elements—Size, color, and style of the font used for the chart title, x-axis title, y-axis title, legend title, description text, legend text, and axis labels. You can change the format for multiple elements at once by pressing Ctrl and clicking to select the elements.
- Symbol elements—Color, width, and style (Solid, Dot, or Dash) for grid and axis lines and the background color of the chart.
General
The General tab 
configurations are used to update the titles for the chart, axes, and legend.
The default titles for charts and axes are based on the variable names and chart type. You can edit or turn off the titles on the General tab. You can also provide a title in the Legend title parameter. The Legend alignment can be set as Right, Left, Top, or Bottom. You can also add a chart description in the Description parameter. A description is a block of text that appears at the bottom of the chart window.
Resources
Use the following resources to learn more about charts:
- Configure charts
- Configure pop-ups to add charts
- Style numbers using Charts or Charts and Size