chart
calendar heatmap
Calendar grid where each day is colored by a value.
Classification
- chart
- matrices and tables › heat matrices
- change over time; Financial Times Visual Vocabulary
- the name evokes: nature, object
Channels
color luminance; main: value of the day
color saturation; main: value of the day (instead of luminance)
spatial region; main: day, week, month (calendar grid)
Attestation
- English definition: Data Visualisation Guide, data.europa.eu
Scientific literature
OpenAlex: 14 papers since 2020, 50% in the last five years; mostly in Computer Science, Business, Management and Accounting, Engineering
Seminal references
R packages
- R
openair::calendarPlot(); GitHub 368 stars; last commit 2026-11; paper (2 011 citations)
R code of the ggplot2 example
library(ggplot2)
library(dplyr)
library(HistData)
## One column per week, Monday first.
cholera <- CholeraDeaths1849 |>
filter(cause_of_death == "Cholera") |>
mutate(week = as.integer(format(date, "%W")),
month = month.abb[as.integer(format(date, "%m"))])
firsts <- cholera |>
filter(day_of_month == "1")
p <- ggplot(cholera, aes(x = week, y = day_of_week, fill = deaths)) +
geom_tile(colour = "white", linewidth = 0.3) +
scale_x_continuous(breaks = firsts$week, labels = firsts$month, expand = c(0, 0), position = "top") +
scale_y_discrete(limits = rev, labels = \(d) ifelse(d %in% c("Mon", "Wed", "Fri"), d, "")) +
scale_fill_continuous(labels = lex_number) +
coord_equal() +
labs(title = "Cholera deaths peaked in the first week of September",
subtitle = "Deaths from cholera each day in England, 1849",
x = NULL, y = NULL, fill = "Deaths per day",
caption = "Data: Farr 1852, via the HistData R package") +
theme_lex_viz(grid = "", arrows = "") +
theme(legend.position = "bottom", legend.key.width = unit(10, "mm"), legend.key.height = unit(2.5, "mm"),
axis.text.x = element_text(hjust = 0))Sources (3)
1 occurrence in the corpus
Cite this entry
Stable addresshttps://dataviz.adrientaudiere.com/en-only/term/calendar-heatmap.html
ReferenceTaudière Adrien. 2026. calendar heatmap. In Visualization Vocabulary, version 1.0.0. IdEst. https://dataviz.adrientaudiere.com/en-only/term/calendar-heatmap.html
BibTeX
@incollection{taudiere2026-calendar-heatmap,
author = {Taudière, Adrien},
title = {calendar heatmap},
booktitle = {Visualization Vocabulary},
year = {2026},
version = {1.0.0},
publisher = {IdEst},
url = {https://dataviz.adrientaudiere.com/en-only/term/calendar-heatmap.html},
note = {CC0 1.0}
}Page created on 2026-10-13. Text last changed on 2026-10-22. Images last changed on 2026-11-12. Numbers computed on 2026-10-22.