holiday-utilities {almanac}

Holiday utility functions

Description

These three functions allow you to tweak existing holidays created by rholiday() so that they more properly align with business calendars. The resulting holidays can then be added into an rcalendar().

• hol_observe() adjusts a holiday based on when it is actually observed. For example, many holidays that occur on a Saturday are actually observed on the preceding Friday or following Monday.

• hol_offset() creates a new holiday by offsetting it from an existing one. For example, Boxing Day is the day after Christmas, and the observance of Boxing Day may be dependent on the observance of Christmas (i.e. if Christmas is Sunday, it may be observed on Monday, so Boxing Day would be observed on Tuesday).

• hol_rename() renames an existing holiday. This is typically useful after a call to hol_offset(), since it doesn't rename the holiday but you may want to give it a different name.

Usage

hol_observe(x, adjust_on, adjustment)

hol_offset(x, by)

hol_rename(x, name)

Arguments

x

⁠[rholiday]⁠

An rholiday.

adjust_on

⁠[rschedule]⁠

An rschedule that determines when the adjustment is to be applied.

adjustment

⁠[function]⁠

An adjustment function to apply to problematic dates. Typically one of the pre-existing adjustment functions, like adj_nearest().

A custom adjustment function must have two arguments x and rschedule. x is the complete vector of dates that possibly need adjustment. rschedule is the rschedule who's event set determines when an adjustment needs to be applied. The function should adjust x as required and return the adjusted Date vector.

by

⁠[integer(1)]⁠

A single integer to offset by.

name

⁠[character(1)]⁠

A new name for the holiday.

Examples

on_weekends <- weekly() %>%
  recur_on_weekends()

# Christmas, adjusted to nearest Friday or Monday if it falls on a weekend
on_christmas <- hol_christmas() %>%
  hol_observe(on_weekends, adj_nearest)

# Boxing Day is the day after Christmas.
# If observed Christmas is a Friday, then observed Boxing Day should be Monday.
# If observed Christmas is a Monday, then observed Boxing Day should be Tuesday.
on_boxing_day <- on_christmas %>%
  hol_offset(1) %>%
  hol_observe(on_weekends, adj_following) %>%
  hol_rename("Boxing Day")

christmas_dates <- alma_events(on_christmas, year = 2010:2015)
boxing_day_dates <- alma_events(on_boxing_day, year = 2010:2015)

data.frame(
  christmas = christmas_dates,
  boxing_day = boxing_day_dates,
  christmas_weekday = lubridate::wday(christmas_dates, label = TRUE),
  boxing_day_weekday = lubridate::wday(boxing_day_dates, label = TRUE)
)