Useful Predicates for Dates

is_first_of_quarter(), is_last_of_quarter(), is_first_of_year() and is_last_of_year() check whether a Date is the first or respectively the last day of a quarter/year. is_quarter_bounds() and is_year_bounds checks whether two Date vectors mark the bounds of (the same) quarters

is_quarter_bounds(first, last)

is_first_of_quarter(x)

is_last_of_quarter(x)

is_year_bounds(first, last)

is_first_of_year(x)

is_last_of_year(x)

is_Date(x)

is_POSIXlt(x)

Arguments

x, first, last	Date vectors

Value

a logical vector

Examples

x <- as.Date(c("2018-01-01", "2018-03-31", "2018-02-14"))
is_first_of_year(x)
#> [1]  TRUE FALSE FALSE
is_first_of_quarter(x)
#> [1]  TRUE FALSE FALSE
is_last_of_quarter(x)
#> [1] FALSE  TRUE FALSE
is_quarter_bounds(x[[1]], x[[2]])
#> [1] TRUE
is_quarter_bounds(x[[2]], x[[3]])
#> [1] FALSE