xts allows natural range-based time quires like this willsh["1979-12-31/2017-12-31"]
Does tidyverse offer something like that?
lubridate has interval class. Any of these can be used to represent the interval from 1979-12-31 to 2017-12-31.
library(dplyr)
library(lubridate)
ival1 <- interval("19791231/20171231")
ival1a <- interval("1979-12-31/2017-12-31")
ival2 <- interval("19791231/P38Y")
ival2a <- interval("1979-12-31/P38Y")
ival3 <- interval(ymd(19791231), ymd(20171231))
ival3a <- interval(ymd("1979-12-31"), ymd("2017-12-31"))
sapply(list(ival1, ival1a, ival2, ival2a, ival3, ival3a), identical, ival1)
## [1] TRUE TRUE TRUE TRUE TRUE TRUE
%within%
can be used to check whether a date falls in an interval.
ymd(c(19791230, 19791231, 19800101, 20171230, 20171231, 20180101)) %within% ival1
## [1] FALSE TRUE TRUE TRUE TRUE FALSE
We can use it like this:
# test input
willsh <- tibble(Date = seq(ymd(19700101), ymd(20210101), by = "10 year"),
year = year(Date))
willsh %>% filter(Date %within% interval("1979-12-31/2017-12-31"))
## # A tibble: 4 x 2
## Date year
## <date> <dbl>
## 1 1980-01-01 1980
## 2 1990-01-01 1990
## 3 2000-01-01 2000
## 4 2010-01-01 2010