Compute days, weeks, or months from a vector of dates. These work for Gregorian
dates, and for some other calendars where it makes sense. In particular, day_of_week
has been implemented for many calendars that contain the concept of a week. Similarly,
day_of_month, day_of_year and days_remaining will work for several calendars.
Usage
day_of_week(date, ...)
day_of_month(date)
day_of_year(date)
days_remaining(date)
week_of_month(date, first_day = "Monday")
week_of_year(date, first_day = "Monday")
month_of_year(date)
year(date)Value
A vector of numerical values for the requested granularity. In the case of day_of_week(), it returns a character vector of the name of the day of the week, or a numeric vector if numeric = TRUE is specified.
Details
week_of_year() returns the ISO 8601 week number with first_day as Monday.
Under this standard, week 1 of a year is defined as the first week with at least 4 days in the year;
equivalently, it is the week containing 4 January. There is no week 0; instead week 1 of a year may
begin in the previous calendar year.
week_of_month() is defined analogously where week 1 of a month is the first week with at least
4 days in the month; equivalently, it is the week containing the 4th day of the month. There is no week 0;
instead week 1 of a month may begin in the previous calendar month.
days_remaining() returns the number of days remaining in the year.
Other functions should be self-explanatory.
Examples
april2025 <- gregorian_date(2025, 4, 1:30)
day_of_week(april2025)
#> [1] "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday" "Sunday"
#> [7] "Monday" "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday"
#> [13] "Sunday" "Monday" "Tuesday" "Wednesday" "Thursday" "Friday"
#> [19] "Saturday" "Sunday" "Monday" "Tuesday" "Wednesday" "Thursday"
#> [25] "Friday" "Saturday" "Sunday" "Monday" "Tuesday" "Wednesday"
day_of_month(april2025)
#> [1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
#> [26] 26 27 28 29 30
day_of_year(april2025)
#> [1] 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109
#> [20] 110 111 112 113 114 115 116 117 118 119 120
days_remaining(april2025)
#> [1] 274 273 272 271 270 269 268 267 266 265 264 263 262 261 260 259 258 257 256
#> [20] 255 254 253 252 251 250 249 248 247 246 245
week_of_month(april2025)
#> [1] 1 1 1 1 1 1 2 2 2 2 2 2 2 3 3 3 3 3 3 3 4 4 4 4 4 4 4 1 1 1
week_of_year(april2025)
#> [1] 14 14 14 14 14 14 15 15 15 15 15 15 15 16 16 16 16 16 16 16 17 17 17 17 17
#> [26] 17 17 18 18 18
month_of_year(april2025)
#> [1] 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4