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Is x a leap year?

Source: R/is_leap_year.R
is_leap_year.Rd

Tests whether a date or year is a leap year.

This returns NA if the corresponding datey would be invalid, including years before 1000 and dates after 3000-01-01.0.

For numerics, this returns NA for years values less than 1000 or greater than 3000.

This is an S3 generic. This package provides methods for:

  • numeric types double and integer (interpreted as calendar years, e.g. 2000.9 means the calendar year 2000), and

  • date types datey, Date, POSIXct and POSIXlt.

Usage

is_leap_year(x)

# Default S3 method
is_leap_year(x)

# S3 method for class 'integer'
is_leap_year(x)

# S3 method for class 'double'
is_leap_year(x)

# S3 method for class 'datey'
is_leap_year(x)

# S3 method for class 'Date'
is_leap_year(x)

# S3 method for class 'POSIXct'
is_leap_year(x)

# S3 method for class 'POSIXlt'
is_leap_year(x)

Arguments

x

A vector date type or numeric year.

Value

NA if x is not interpretable as a year or date, or outside [1000,3000], TRUE if x is a leap year, otherwise FALSE.

See also

datey

Examples

any(is_leap_year(c(1900, 1901, 2001))) #FALSE
#> [1] FALSE
all(is_leap_year(c(1904.1, 2000.5, 2004.9))) #TRUE
#> [1] TRUE