roffset: Create an offset rschedule

In almanac: Tools for Working with Recurrence Rules

Create an offset rschedule

Description

roffset() creates a new rschedule with events that are offset from an existing rschedule by a certain amount. This can be useful when generating relative events like "the day after Christmas."

Usage

roffset(rschedule, by)

Arguments

rschedule	⁠[rschedule]⁠ An rschedule to offset.
by	⁠[integer(1)]⁠ A single integer to offset by.

Value

An offset rschedule.

Examples

on_christmas <- yearly() %>%
  recur_on_month_of_year("Dec") %>%
  recur_on_day_of_month(25)

on_day_after_christmas <- roffset(on_christmas, by = 1)

alma_search("2018-01-01", "2023-01-01", on_day_after_christmas)

# Now what if you want the observed holiday representing the day after
# Christmas?
on_weekends <- weekly() %>% recur_on_weekends()

# Adjust Christmas to the nearest weekday
on_christmas <- radjusted(on_christmas, on_weekends, adj_nearest)

# Offset by 1 and then adjust that to the following weekday.
# We never adjust backwards because that can coincide with the observed day
# for Christmas.
on_day_after_christmas <- on_christmas %>%
  roffset(by = 1) %>%
  radjusted(on_weekends, adj_following)

# Note that:
# - A Christmas on Friday the 24th resulted in a day after Christmas of
#   Monday the 27th
# - A Christmas on Monday the 26th resulted in a day after Christmas of
#   Tuesday the 27th
christmas <- alma_search("2018-01-01", "2023-01-01", on_christmas)
day_after_christmas <- alma_search("2018-01-01", "2023-01-01", on_day_after_christmas)

lubridate::wday(christmas, label = TRUE)
lubridate::wday(day_after_christmas, label = TRUE)

almanac documentation built on April 14, 2023, 12:23 a.m.