Ribbon plot of 2017 daily sunrise and sunset at RDU airport

sunrise-sunset-2017-RDU.R

# load packages
library(maptools)
library(lubridate)
library(ggplot2)

# vector of all the days in 2017
days <- seq(from = as.POSIXct("2017-01-01"), to = as.POSIXct("2017-12-31"), by = "days")

# coordinates of RDU airport
lon <- -78.788
lat <- 35.8801
coord <- matrix(c(lon, lat), nrow = 1)

# compute sunrise and sunet times for every day
ds <- data.frame(
  date = days,
  sunrise <- sunriset(coord, days, direction = "sunrise", POSIXct.out = TRUE)$time,
  sunset <- sunriset(coord, days, direction = "sunset", POSIXct.out = TRUE)$time
)

# strip date information from sunrise and sunset columns
ds$sunrise <- hms(as.character(ds$sunrise, format = "%H:%M:%S"))
ds$sunset <- hms(as.character(ds$sunset, format = "%H:%M:%S"))

# plot the result
ggplot(ds, aes(x = date, ymin = sunrise, ymax = sunset)) +
  labs(
    title = "2017 Daily Sunrise and Sunset",
    subtitle = "Raleigh-Durham International Airport, North Carolina, United States"
  ) +
  geom_ribbon(fill = "orange") + 
  scale_x_datetime(
    name = "Date",
    date_labels = "%b",
    date_breaks = "1 month",
    minor_breaks = NULL
  ) +
  scale_y_time(
    name = "Time",
    breaks = hm(paste(seq(from = 0, to = 24, by = 2), 0)),
    labels = function(t) sprintf("%02d:%02d", hour(t), minute(t)),
    limits = c(hm("0 45"), hm("23 15"))
  )

The discontinuities represent the beginning and end of daylight saving time (Mar 12 and Nov 5). They are slightly off from vertical because ggplot2::geom_ribbon cannot plot step functions.