lt_date: Format Date/Time Columns

In lt: Lightweight Tables via JSON Specs and JavaScript

Format Date/Time Columns

Description

Format date or datetime columns using JavaScript's native Date methods. The underlying data should be Date or POSIXt in R (serialized as ⁠new Date(...)⁠ for the browser).

Usage

lt_date(x, columns, method = NULL, locale = NULL, options = NULL)

Arguments

x	An lt() object.
columns	Column selection (formula, character, or numeric).
method	A JS Date method name to call (e.g., "toLocaleDateString", "toISOString", "toDateString", "toLocaleString", "toLocaleTimeString"). If NULL (the default), toLocaleDateString() is used with locale and options. See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#instance_methods for all available methods.
locale	A BCP 47 locale string (e.g., "en-US", "de-DE", "ja-JP"). Only used when method is NULL. See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#locales_argument for details.
options	A named list of Intl.DateTimeFormat options. Common fields include year ("numeric", "2-digit"), month ("numeric", "2-digit", "long", "short", "narrow"), day ("numeric", "2-digit"), hour, minute, second ("numeric", "2-digit"), weekday ("long", "short", "narrow"), and timeZoneName ("long", "short"). Only used when method is NULL.

Value

x with the date formatting recorded.

Note

The formatted date may differ from the input date depending on the viewer's local timezone. JavaScript's ⁠new Date("2024-01-15")⁠ parses date-only strings as UTC midnight, but toLocaleDateString() converts to the local timezone. For example, 2024-01-15 will display as 2024-01-14 for a viewer at GMT-6. To avoid this, pass options = list(timeZone = "UTC").

Examples

d = data.frame(
  event = c("Launch", "Update"),
  date = as.Date(c("2024-01-15", "2024-06-30"))
)
lt(d) |> lt_date(~ date)
lt(d) |> lt_date(~ date, options = list(year = "numeric", month = "short"))

lt documentation built on July 10, 2026, 1:09 a.m.