This is a thin wrapper around a lubridate::floor_date() that works
for hms, yearmon, and yearqtr classes as well.
floor_index(x, unit = "seconds")a vector of date-time objects
a string, Period object or a date-time object. When a singleton string,
it specifies a time unit or a multiple of a unit to be rounded to. Valid base units
are second, minute, hour, day, week, month, bimonth, quarter,
season, halfyear and year. Arbitrary unique English abbreviations as in the
period() constructor are allowed. Rounding to multiples of units (except weeks)
is supported. When unit is a Period object, units of the period objects are
used. This is equivalent to converting the period object to its string
representation and passing as unit argument.
When unit is a date-time object rounding is done to the nearest of the
elements in unit. If range of unit vector does not cover the range of
x ceiling_date() and floor_date() round to the max(x) and min(x)
for elements that fall outside of range(unit).
data(FB)
dplyr::mutate(FB, date2 = floor_index(date, "year"))
#> # A tibble: 1,008 × 9
#> symbol date open high low close volume adjusted date2
#> <chr> <date> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <date>
#> 1 FB 2013-01-02 27.4 28.2 27.4 28 69846400 28 2013-01-01
#> 2 FB 2013-01-03 27.9 28.5 27.6 27.8 63140600 27.8 2013-01-01
#> 3 FB 2013-01-04 28.0 28.9 27.8 28.8 72715400 28.8 2013-01-01
#> 4 FB 2013-01-07 28.7 29.8 28.6 29.4 83781800 29.4 2013-01-01
#> 5 FB 2013-01-08 29.5 29.6 28.9 29.1 45871300 29.1 2013-01-01
#> 6 FB 2013-01-09 29.7 30.6 29.5 30.6 104787700 30.6 2013-01-01
#> 7 FB 2013-01-10 30.6 31.5 30.3 31.3 95316400 31.3 2013-01-01
#> 8 FB 2013-01-11 31.3 32.0 31.1 31.7 89598000 31.7 2013-01-01
#> 9 FB 2013-01-14 32.1 32.2 30.6 31.0 98892800 31.0 2013-01-01
#> 10 FB 2013-01-15 30.6 31.7 29.9 30.1 173242600 30.1 2013-01-01
#> # … with 998 more rows
time_test <- create_series('00:00:00'~'12:00:00',
'1 minute', class = "hms")
dplyr::mutate(time_test, date2 = floor_index(date, "hour"))
#> # A time tibble: 721 × 2
#> # Index: date
#> date date2
#> <time> <time>
#> 1 00'00" 00'00"
#> 2 01'00" 00'00"
#> 3 02'00" 00'00"
#> 4 03'00" 00'00"
#> 5 04'00" 00'00"
#> 6 05'00" 00'00"
#> 7 06'00" 00'00"
#> 8 07'00" 00'00"
#> 9 08'00" 00'00"
#> 10 09'00" 00'00"
#> # … with 711 more rows