NZHolidays.R

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+# Functions to calculate if a date
+# is a holiday or weekend.
+# Functions are vectorised, so can
+# be used with columns of dates.
+
+# Note: Holidays are mondayised if they fall on weekends
+# and the Saturday/Sunday parts of Easter are excluded.
+# Change the code if this is not the way you want it to work.
+
+# Note: Mondayisation for ANZAC and Waitangi were introduced
+# only in 2015 and 2016 respectively. Non-mondayised versions
+# of these holidays are trivial to calculate.
+
+# Note: This file includes code to calculate
+# Wellington Anniversary weekend, although it is not
+# included in the is.NZHoliday function. No other anniversary
+# days are included at this time.
+
+library(timeDate) # For Easter calculation
+
+# Determine if a given day is a weekend
+is.Weekend <- function(x) {
+  return(weekdays(x) %in% c("Saturday", "Sunday"))
+}
+
+# Determine if a given date is in the 
+# range easter friday to easter monday inclusive.
+# Note that this includes the whole weekend
+is.Easter <- function(x) {
+  year <- as.numeric(format(x, "%Y"))
+  date.easter <- as.Date(timeDate::Easter(year))
+  # Make this (-2:2) to include Easter Tuesday
+  # (not a public holiday, but it is for e.g.
+  # schoolchildren.)
+  # Change to c(-2:1) to include weekend
+  return((x - date.easter) %in% c(-2, 1))
+}
+
+# Determine if a given day is Waitangi 
+# day (observed), i.e. the following 
+# Monday if on weekend (from 2016)
+is.Waitangi <- function(x) {
+  yearstr <- format(x, "%Y")
+  year <- as.numeric(yearstr)
+  date.wait <- as.Date(paste0(yearstr, "-02-06"))
+  day.wait <- weekdays(date.wait)
+  date.hol <- ifelse(day.wait == "Saturday", 
+                     date.wait + 2, 
+                     ifelse(day.wait=="Sunday", 
+                            date.wait + 1, 
+                            date.wait))
+  return(ifelse(year >= 2016, x == date.hol, x == date.wait))
+}
+
+# Mondayised ANZAC
+is.ANZAC <- function(x) {
+  yearstr <- format(x, "%Y")
+  year <- as.numeric(yearstr)
+  date.anzac <- as.Date(paste0(yearstr, "-04-25"))
+  day.anzac <- weekdays(date.anzac)
+  date.hol <- ifelse(day.anzac == "Saturday", 
+                     date.anzac + 2, 
+                     ifelse(day.anzac=="Sunday", 
+                            date.anzac + 1, 
+                            date.anzac))
+  return(ifelse(year >= 2015, x == date.hol, x == date.anzac))
+}
+
+# Determine if a given day is Labour day
+is.Labour <- function(x) {
+  is.oct <- months(x) == "October"
+  month.day <- as.numeric(format(x, "%d"))
+  dow <- weekdays(x)
+  week <- ((month.day - 1) %/% 7) + 1
+  return(is.oct & (dow == "Monday") & (week == 4))
+}
+
+# Determine if a given day is Queens birthday
+is.QB <- function(x) {
+  is.jun <- months(x) == "June"
+  month.day <- as.numeric(format(x, "%d"))
+  dow <- weekdays(x)
+  week <- ((month.day - 1) %/% 7) + 1
+  return(is.jun & (dow == "Monday") & (week == 1))
+}
+
+# Determine if christmas day (observed)
+is.Christmas <- function(x) {
+  yearstr <- format(x, "%Y")
+  date.chris <- as.Date(paste0(yearstr, "-12-25"))
+  day.chris <- weekdays(date.chris)
+  date.hol <- ifelse(day.chris == "Saturday", 
+                     date.chris + 2, 
+                     ifelse(day.chris=="Sunday", 
+                            date.chris + 1, 
+                            date.chris))
+  return(x == date.hol)
+}
+
+# Determine if boxing day (observed)
+is.Boxing <- function(x) {
+  yearstr <- format(x, "%Y")
+  date.box <- as.Date(paste0(yearstr, "-12-26"))
+  day.box <- weekdays(date.box)
+  date.hol <- ifelse(day.box %in% c("Saturday", "Sunday"),
+                     date.box + 2, 
+                     ifelse(day.box=="Monday", 
+                            date.box + 1, 
+                            date.box))
+  return(x == date.hol)
+}
+
+# Determine if new years day (observed)
+is.NewYears <- function(x) {
+  yearstr <- format(x, "%Y")
+  date.ny <- as.Date(paste0(yearstr, "-01-01"))
+  day.ny <- weekdays(date.ny)
+  date.hol <- ifelse(day.ny == "Saturday", 
+                     date.ny + 2, 
+                     ifelse(day.ny=="Sunday", 
+                            date.ny + 1, 
+                            date.ny))
+  return(x == date.hol)
+}
+
+# Determine if new years day plus one (observed)
+is.NewYearsPlusOne <- function(x) {
+  yearstr <- format(x, "%Y")
+  date.nyp1 <- as.Date(paste0(yearstr, "-01-02"))
+  day.nyp1 <- weekdays(date.nyp1)
+  date.hol <- ifelse(day.nyp1 %in% c("Saturday", "Sunday"),
+                     date.nyp1 + 2, 
+                     ifelse(day.nyp1=="Monday", 
+                            date.nyp1 + 1, 
+                            date.nyp1))
+  return(x == date.hol)
+}
+
+# Determine if date is wellington
+# anniversary, i.e closest
+# Monday to the 22nd of Jan.
+is.WellingtonAnn <- function(x) {
+  yearstr <- format(x, "%Y")
+  date.theory <- as.Date(paste0(yearstr, "-01-22"))
+  day.x <- weekdays(x)
+  return(day.x == "Monday" & abs(x - date.theory) < 4)
+}
+
+# Determines if day is an NZ
+# Public holiday
+is.NZHoliday <- function(x) {
+  is.Easter(x) | is.Waitangi(x) | is.ANZAC(x) |
+    is.Labour(x) | is.QB(x) | is.Christmas(x) |
+    is.Boxing(x) | is.NewYears(x) | is.NewYearsPlusOne(x)
+}
+
+# NZHoliday, but includes Well Ann.
+is.WellHoliday <- function(x) {
+  is.NZHoliday(x) | is.WellingtonAnn(x)
+}