calendar_leap_year {clock}

Is the calendar year a leap year?

Description

calendar_leap_year() detects if the calendar year is a leap year - i.e. does it contain one or more extra components than other years?

A particular year is a leap year if:

• year_month_day(): February has 29 days.

• year_month_weekday(): February has a weekday that occurs 5 times.

• year_week_day(): There are 53 weeks in the year, resulting in 371 days in the year.

• iso_year_week_day(): There are 53 weeks in the year, resulting in 371 days in the year.

• year_quarter_day(): One of the quarters has 1 more day than normal (the quarter with an extra day depends on the start used, but will always be the same for a particular start). This aligns with Gregorian leap years for all starts except February, in which case the leap year is always 1 year after the Gregorian leap year.

• year_day(): There are 366 days in the year.

Usage

calendar_leap_year(x)

Arguments

x

⁠[calendar]⁠

A calendar type to detect leap years in.

Value

A logical vector the same size as x. Returns TRUE if in a leap year, FALSE if not in a leap year, and NA if x is NA.

Examples

x <- year_month_day(c(2019:2024, NA))
calendar_leap_year(x)

# For year-quarter-day, the leap year typically aligns with the Gregorian
# leap year, unless the `start` is February, in which case the leap year is
# always 1 year after the Gregorian leap year
x <- year_quarter_day(2020:2021, start = clock_months$january)
calendar_leap_year(x)

x <- year_quarter_day(2020:2021, start = clock_months$february)
calendar_leap_year(x)

# With a January start, 2020 has the extra day
get_day(year_quarter_day(2020, 1:4, "last", start = clock_months$january))
get_day(year_quarter_day(2021, 1:4, "last", start = clock_months$january))
get_day(year_quarter_day(2022, 1:4, "last", start = clock_months$january))

# With a February start, 2021 has the extra day
get_day(year_quarter_day(2020, 1:4, "last", start = clock_months$february))
get_day(year_quarter_day(2021, 1:4, "last", start = clock_months$february))
get_day(year_quarter_day(2022, 1:4, "last", start = clock_months$february))