recur_on_wday() recurs on a specific day of the week.
recur_on_weekends() and recur_on_weekdays() are helpers for
recurring on weekends and weekdays.
recur_on_wday(x, wday, nth = NULL)
recur_on_weekdays(x)
recur_on_weekends(x)[rrule]
A recurrence rule.
[integer / character]
Days of the week to recur on. Integer values must be from 1 to 7, with
1 = Monday and 7 = Sunday. This is also allowed to be a full weekday
string like "Tuesday", or an abbreviation like "Tues".
[integer / NULL]
Limit to the n-th occurrence of the wday in the base frequency. For
example, in a monthly frequency, using nth = -1 would limit to the
last wday in the month. The default of NULL chooses all occurrences.
An updated rrule.
Multiple week day values are allowed, and nth will be applied to
all of them. If you want to apply different nth values to different
days of the week, call recur_on_wday() twice with different wday values.
It is particularly important to pay attention to the since date when using
weekly rules. The day of the week to use comes from the since date, which,
by default, is a Monday (1900-01-01).
# Using default `since` (1900-01-01, a Monday)
on_weekly_mondays <- weekly()
start <- "1999-01-01" # <- a Friday
end <- "1999-03-01"
# This finds the first Thursday, and then continues from there
alma_search(start, end, on_weekly_mondays)
#> [1] "1999-01-04" "1999-01-11" "1999-01-18" "1999-01-25" "1999-02-01"
#> [6] "1999-02-08" "1999-02-15" "1999-02-22" "1999-03-01"
# We start counting from a Friday here
on_weekly_fridays <- weekly(since = start)
alma_search(start, end, on_weekly_fridays)
#> [1] "1999-01-01" "1999-01-08" "1999-01-15" "1999-01-22" "1999-01-29"
#> [6] "1999-02-05" "1999-02-12" "1999-02-19" "1999-02-26"
# Alternatively, we could use `recur_on_wday()` and force a recurrence rule
# on Friday
on_wday_friday <- on_weekly_mondays %>% recur_on_wday("Friday")
alma_search(start, end, on_wday_friday)
#> [1] "1999-01-01" "1999-01-08" "1999-01-15" "1999-01-22" "1999-01-29"
#> [6] "1999-02-05" "1999-02-12" "1999-02-19" "1999-02-26"
# At monthly frequencies, you can use n-th values to look for particular
# week day events
on_first_friday_in_month <- monthly() %>% recur_on_wday("Fri", 1)
alma_search(start, end, on_first_friday_in_month)
#> [1] "1999-01-01" "1999-02-05"
# Negative values let you look from the back
on_last_friday_in_month <- monthly() %>% recur_on_wday("Fri", -1)
alma_search(start, end, on_last_friday_in_month)
#> [1] "1999-01-29" "1999-02-26"
# At yearly frequencies, this looks for the first sunday of the year
on_first_sunday_in_year <- yearly() %>% recur_on_wday("Sunday", 1)
alma_search(start, end, on_first_sunday_in_year)
#> [1] "1999-01-03"
# Last week day of the month
last_weekday_of_month <- monthly() %>%
# Last occurrence of each weekday in the month
recur_on_wday(c("Mon", "Tue", "Wed", "Thu", "Fri"), -1) %>%
# Now choose the last one of those in each month
recur_on_position(-1)
alma_search(start, end, last_weekday_of_month)
#> [1] "1999-01-29" "1999-02-26"