recur_on_week_of_year() recurs on a specific week of the year.
Arguments
- x
[rrule]A recurrence rule.
- week
[integer]Weeks of the year to recur on. Integer values must be between
[1, 53]or[-53, -1].
Details
Weekly rules are implemented according to the ISO-8601 standard. This
requires that the first week of a year is the first one containing at least
4 days of the new year. Additionally, the week will start on the week day
specified by recur_with_week_start(), which defaults to Monday.
Examples
# Weekly rules are a bit tricky because they are implemented to comply
# with ISO-8601 standards, which require that the first week of the year
# is when there are at least 4 days in that year, and the week starts on
# the week day specified by `recur_with_week_start()` (Monday by default).
on_first_week <- yearly() %>% recur_on_week_of_year(1)
# In 2017:
# - Look at dates 1-4
# - 2017-01-02 is a Monday, so start the first week here
alma_search("2017-01-01", "2017-01-25", on_first_week)
#> [1] "2017-01-02" "2017-01-03" "2017-01-04" "2017-01-05" "2017-01-06"
#> [6] "2017-01-07" "2017-01-08"
# In 2015:
# - Look at dates 1-4
# - None of these are Monday, so the start of the week is
# in the previous year
# - Look at 2014 and find the last Monday, 2014-12-29. This is the start of
# the first week in 2015.
alma_search("2014-12-25", "2015-01-25", on_first_week)
#> [1] "2014-12-29" "2014-12-30" "2014-12-31" "2015-01-01" "2015-01-02"
#> [6] "2015-01-03" "2015-01-04"
# Say we want the start of the week to be Sunday instead of Monday!
# In 2015:
# - Look at dates 1-4
# - 2015-01-04 is a Sunday, so start the first week here
on_first_week_sun <- yearly() %>%
recur_on_week_of_year(1) %>%
recur_with_week_start("Sunday")
alma_search("2014-12-25", "2015-01-25", on_first_week_sun)
#> [1] "2015-01-04" "2015-01-05" "2015-01-06" "2015-01-07" "2015-01-08"
#> [6] "2015-01-09" "2015-01-10"