Gantt chart

R code of the ggplot2 example

library(ggplot2)
library(dplyr)

## An invented schedule: an environmental DNA survey over one year, from the
## permits to the report.
tasks <- tribble(
  ~task, ~phase, ~start, ~end,
  "Sampling permits", "Field", "2026-01-05", "2026-02-27",
  "Field campaign 1", "Field", "2026-04-06", "2026-04-24",
  "Field campaign 2", "Field", "2026-06-08", "2026-06-26",
  "Field campaign 3", "Field", "2026-09-07", "2026-09-25",
  "DNA extraction", "Laboratory", "2026-04-27", "2026-10-16",
  "Sequencing", "Laboratory", "2026-10-19", "2026-11-13",
  "Bioinformatics", "Analysis", "2026-11-16", "2026-12-18",
  "Report", "Analysis", "2026-12-07", "2027-01-29"
) |>
  mutate(across(c(start, end), as.Date),
         task = factor(task, levels = rev(task)),
         phase = factor(phase, levels = c("Field", "Laboratory", "Analysis")))

p <- ggplot(tasks, aes(y = task, colour = phase)) +
  geom_segment(aes(x = start, xend = end), linewidth = 4.5) +
  scale_colour_manual(values = unname(lex_colors), name = NULL) +
  scale_x_date(date_breaks = "2 months", labels = scales::label_date("%b %Y", locale = "en"),
               expand = expansion(mult = c(0.02, 0.08))) +
  labs(title = "DNA extraction runs from the first field campaign\nto after the third",
       subtitle = "Schedule of an environmental DNA survey, by task",
       x = NULL, y = NULL,
       caption = "Data: invented for the example") +
  theme_lex_viz(grid = "x", arrows = "x")