How could I count dates based on some condition?

Question

I have two date variable one is question open date and another is question answered date, like follows:

   q_open     q_answer
2020-09-01   2020-09-02
2020-09-01   2020-09-09
2020-09-05      NA
2020-09-10   2020-09-17

I need to find out the counts of the question that are not answered within a week. The week starts from the min(q_open). So week one starts from 2020-09-01 and ends on 2020-09-07. So the desired output is:

Week   count_answered
 1         2           # considering NA also
 2         1

Thanks in advance.

Answer 1

How about this:

library(dplyr)
library(lubridate)
library(tibble)

data <- tibble(
  q_open = as.Date(c("2020-09-01", "2020-09-01", "2020-09-05", "2020-09-10")),
  q_answer = as.Date(c("2020-09-02", "2020-09-09", NA, "2020-09-17"))
)

out <- data %>%
  mutate(wk_open = week(q_open),
         wk_answer = week(q_answer)) %>%
  mutate(on_time = ifelse(wk_answer >= wk_open + 1, TRUE, FALSE )) %>%
  group_by(wk_open) %>%
  summarise(count_answered = sum(on_time, na.rm = TRUE))

with:

> out
# A tibble: 3 x 2
  wk_open count_answered
    <dbl>          <int>
1      35              2
2      36              0
3      37              1