R: how to filter a timestamp by hour and minute?

ℕʘʘḆḽḘ picture ℕʘʘḆḽḘ · Jan 4, 2017 · Viewed 10k times · Source

I am struggling with the following example

time = c('2013-01-03 21:59:21.549', '2013-01-04 22:00:21.549', '2013-01-05 22:01:21.222', '2013-01-06 22:06:23.559' )
value = c(1,2,3,4)

data <- data_frame(time, value)
data <-data %>%  mutate(time = ymd_hms(time))

> data
# A tibble: 4 × 2
                 time value
               <dttm> <dbl>
1 2013-01-03 21:59:21     1
2 2013-01-04 22:00:21     2
3 2013-01-05 22:01:21     3
4 2013-01-06 22:06:23     4

How can I write a dplyr::filter statement than only keeps observations between 21:59 and 22:01 (included) every day?

Playing separately with hour(time) and minute(time) does not seem to work very well here.

Am I missing something here?

Output expected: row 1,2 and 3 only. Thanks!

Answer

ℕʘʘḆḽḘ picture ℕʘʘḆḽḘ · Jan 18, 2019

2019 is here! Here is a better (and simpler) solution using as.hms. The tz argument is mandatory.

    time_str = c('2013-01-03 21:59:21.549', '2013-01-04 22:00:21.549', '2013-01-05 
    22:01:21.222', '2013-01-06 22:06:23.559' )
    value = c(1,2,3,4)
    data <- tibble(time_str, value)

    data %>%  mutate(timestamp_utc = ymd_hms(time_str, tz = 'UTC'),
                     timestamp_est = with_tz(timestamp_utc, 'America/New_York'),
                            time_est = as.hms(timestamp_est, tz = 'America/New_York')) %>% 
      filter(time_est >= hms::as.hms('16:59:00', tz = 'America/New_York'),
             time_est <= hms::as.hms('17:01:00', tz = 'America/New_York'))

will do the job

# A tibble: 2 x 5
  time_str                value timestamp_utc           timestamp_est           time_est 
  <chr>                   <dbl> <dttm>                  <dttm>                  <time>   
1 2013-01-03 21:59:21.549     1 2013-01-03 21:59:21.549 2013-01-03 16:59:21.549 16:59.549
2 2013-01-04 22:00:21.549     2 2013-01-04 22:00:21.549 2013-01-04 17:00:21.549 17:00.549