Generating a Google Sunset Calendar using R on Ubuntu

Notes for generating a Google Sunset Calendar using R. Note, I adjusted the start time 10 min earlier. Thanks to Hilary Parker
sudo apt-key adv --keyserver --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9
#sudo add-apt-repository 'deb [arch=amd64,i386] trusty/'
#sudo add-apt-repository 'deb [arch=amd64,i386] xenial/'
sudo apt update
sudo apt upgrade
sudo apt install r-base
vi create_sunset_cal.R
sudo -i R
head /YourPath/sunset.csv
Subject,Start Date,Start Time,End Date,End Time,All Day Event,Description,Location,Private
Sunset,2017-09-03,19:47:54 PM,2017-09-03,20:27:54 PM,False,Sunset Calendar,YourAddress,False
Sunset,2017-09-04,19:46:24 PM,2017-09-04,20:26:24 PM,False,Sunset Calendar,YourAddress,False
Sunset,2017-09-05,19:44:54 PM,2017-09-05,20:24:54 PM,False,Sunset Calendar,YourAddress,False

cat /YourPath/create_sunset_cal.R
#' Create a sunset calendar
#' This function creates a .CSV of sunset appointments--with a user-specified location--that can be imported into Google Calendar.
#' @param date Date at which you want the calendar to start, in yyyy/mm/dd format.
#' @param lat Latitude of location (for sunset time calculation)
#' @param long Longitude of location (for sunset time calculation, will be negative for continental US)
#' @param timezone Timezone of location (for sunset time calculation).
#' @param num.days Number of days you want sunset appointments for.
#' @param file Filename for outputted .CSV file (to be uploaded to Google Calendar).
#' @param location Location of sunset appointment. Will be input into Google Calendar event as the event location.
#' @importFrom StreamMetabolism sunrise.set
#' @export
#' @examples \dontrun{
#' create_sunset_cal(location = "40.7127, -74.0059")

create_sunset_cal <- function(date="2017/09/03",
                              lat = 40.7127,
                              long = -74.0059,
                              timezone = "America/Denver",
                              num.days = 365,
                              location = "YourAddress"){

  location <- gsub(",", "", location)

  dates <- seq(
    by = "day",
    length.out = num.days

  sunset_times <- sunrise.set(
    lat = lat,
    long = long,
    date = date,
    timezone = timezone,
    num.days = num.days

  nms <- c(
    'Start Date',
    'Start Time',
    'End Date',
    'End Time',
    'All Day Event',
  mat <- matrix(
    nrow = length(dates),
    ncol = length(nms)
  mat <- data.frame(mat)
  colnames(mat) <- nms

  mat$Subject <- "Sunset"
  mat$"Start Date" <- dates
  mat$"End Date" <- dates
  mat$"All Day Event" <- "False"
  mat$Description <- "Sunset Calendar"
  mat$Location <- location
  mat$Private <- "False"

  starts <- strftime(sunset_times-60*10, format="%H:%M:%S %p")
  ends <- strftime(sunset_times+60*30, format="%H:%M:%S %p")
  mat$"Start Time" <- starts
  mat$"End Time" <- ends



Time problems when dual booting Ubuntu Linux and Windows 10

Some OS like Linux set the hardware clock to UTC.  Others like Windows use Local time.  There are several ways to work around this issue but the easiest for me is below:

Make Linux use 'Local' time

To tell your Ubuntu system that the hardware clock is set to 'local' time:

Pre-Ubuntu 15.04 systems (e.g. Ubuntu 14.04 LTS):

  1. edit /etc/default/rcS
  2. add or change the following section
    # Set UTC=yes if your hardware clock is set to UTC (GMT)

Ubuntu 15.04 systems and above (e.g. Ubuntu 16.04 LTS):

  1. open a terminal and execute the following command
    timedatectl set-local-rtc 1