Format a vector as date values

Format vector values to date values using one of 41 preset date styles. Input can be in the form of POSIXt (i.e., datetimes), the Date type, or character (must be in the ISO 8601 form of YYYY-MM-DD HH:MM:SS or YYYY-MM-DD).

Usage

vec_fmt_date(
  x,
  date_style = "iso",
  pattern = "{x}",
  locale = NULL,
  output = c("auto", "plain", "html", "latex", "rtf", "word")
)

Arguments

x

The input vector

vector(numeric|integer) // required

This is the input vector that will undergo transformation to a character vector of the same length. Values within the vector will be formatted.

date_style

Predefined style for dates

scalar<character>|scalar<numeric|integer>(1<=val<=41) // default: "iso"

The date style to use. By default this is the short name "iso" which corresponds to ISO 8601 date formatting. There are 41 date styles in total and their short names can be viewed using info_date_style().

pattern

Specification of the formatting pattern

scalar<character> // default: "{x}"

A formatting pattern that allows for decoration of the formatted value. The formatted value is represented by the {x} (which can be used multiple times, if needed) and all other characters will be interpreted as string literals.

locale

Locale identifier

scalar<character> // default: NULL (optional)

An optional locale identifier that can be used for formatting values according to the locale's rules. Examples include "en" for English (United States) and "fr" for French (France). We can call info_locales() for a useful reference for all of the locales that are supported.

output

Output format

The output style of the resulting character vector. This can either be "auto" (the default), "plain", "html", "latex", "rtf", or "word". In knitr rendering (i.e., Quarto or R Markdown), the "auto" option will choose the correct output value

Value

A character vector.

Formatting with the `date_style` argument

We need to supply a preset date style to the date_style argument. The date styles are numerous and can handle localization to any supported locale. A large segment of date styles are termed flexible date formats and this means that their output will adapt to any locale provided. That feature makes the flexible date formats a better option for locales other than "en" (the default locale).

The following table provides a listing of all date styles and their output values (corresponding to an input date of 2000-02-29).

	Date Style	Output	Notes
1	`"iso"`	`"2000-02-29"`	ISO 8601
2	`"wday_month_day_year"`	`"Tuesday, February 29, 2000"`
3	`"wd_m_day_year"`	`"Tue, Feb 29, 2000"`
4	`"wday_day_month_year"`	`"Tuesday 29 February 2000"`
5	`"month_day_year"`	`"February 29, 2000"`
6	`"m_day_year"`	`"Feb 29, 2000"`
7	`"day_m_year"`	`"29 Feb 2000"`
8	`"day_month_year"`	`"29 February 2000"`
9	`"day_month"`	`"29 February"`
10	`"day_m"`	`"29 Feb"`
11	`"year"`	`"2000"`
12	`"month"`	`"February"`
13	`"day"`	`"29"`
14	`"year.mn.day"`	`"2000/02/29"`
15	`"y.mn.day"`	`"00/02/29"`
16	`"year_week"`	`"2000-W09"`
17	`"year_quarter"`	`"2000-Q1"`
18	`"yMd"`	`"2/29/2000"`	flexible
19	`"yMEd"`	`"Tue, 2/29/2000"`	flexible
20	`"yMMM"`	`"Feb 2000"`	flexible
21	`"yMMMM"`	`"February 2000"`	flexible
22	`"yMMMd"`	`"Feb 29, 2000"`	flexible
23	`"yMMMEd"`	`"Tue, Feb 29, 2000"`	flexible
24	`"GyMd"`	`"2/29/2000 A"`	flexible
25	`"GyMMMd"`	`"Feb 29, 2000 AD"`	flexible
26	`"GyMMMEd"`	`"Tue, Feb 29, 2000 AD"`	flexible
27	`"yM"`	`"2/2000"`	flexible
28	`"Md"`	`"2/29"`	flexible
29	`"MEd"`	`"Tue, 2/29"`	flexible
30	`"MMMd"`	`"Feb 29"`	flexible
31	`"MMMEd"`	`"Tue, Feb 29"`	flexible
32	`"MMMMd"`	`"February 29"`	flexible
33	`"GyMMM"`	`"Feb 2000 AD"`	flexible
34	`"yQQQ"`	`"Q1 2000"`	flexible
35	`"yQQQQ"`	`"1st quarter 2000"`	flexible
36	`"Gy"`	`"2000 AD"`	flexible
37	`"y"`	`"2000"`	flexible
38	`"M"`	`"2"`	flexible
39	`"MMM"`	`"Feb"`	flexible
40	`"d"`	`"29"`	flexible
41	`"Ed"`	`"29 Tue"`	flexible

We can call info_date_style() in the console to view a similar table of date styles with example output.

Examples

Let's create a character vector of dates in the ISO-8601 format for the next few examples:

str_vals <- c("2022-06-13", "2019-01-25", "2015-03-23", NA)

Using vec_fmt_date() (here with the "wday_month_day_year" date style) will result in a character vector of formatted dates. Any NA values remain as NA values. The rendering context will be autodetected unless specified in the output argument (here, it is of the "plain" output type).

vec_fmt_date(str_vals, date_style = "wday_month_day_year")

#> [1] "Monday, June 13, 2022" "Friday, January 25, 2019"
#> [3] "Monday, March 23, 2015" NA

We can choose from any of 41 different date formatting styles. Many of these styles are flexible, meaning that the structure of the format will adapt to different locales. Let's use the "yMMMEd" date style to demonstrate this (first in the default locale of "en"):

vec_fmt_date(str_vals, date_style = "yMMMEd")

#> [1] "Mon, Jun 13, 2022" "Fri, Jan 25, 2019" "Mon, Mar 23, 2015" NA

Let's perform the same type of formatting in the French ("fr") locale:

vec_fmt_date(str_vals, date_style = "yMMMEd", locale = "fr")

#> [1] "lun. 13 juin 2022" "ven. 25 janv. 2019" "lun. 23 mars 2015" NA

We can always use info_date_style() to call up an info table that serves as a handy reference to all of the date_style options.

As a last example, one can wrap the date values in a pattern with the pattern argument. Note here that NA values won't have the pattern applied.

vec_fmt_date(str_vals, pattern = "Date: {x}")

#> [1] "Date: 2022-06-13" "Date: 2019-01-25" "Date: 2015-03-23" NA

Function ID

15-13

Function Introduced

v0.7.0 (Aug 25, 2022)