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Generate candidate date format strings for as.Date()

Source: R/utils.R
make_date_fmts.Rd

Builds a set of possible format strings suitable for as.Date() for a given day/month/year order. This is intended for fast "detect once per sheet, then parse all" workflows.

Usage

make_date_fmts(order)

Arguments

order

A single string specifying the component order as a permutation of "d", "y", and exactly one of "m" or "M" (e.g. "dmy", "ymd", "dMy", "Mdy").

Value

A character vector of unique date format strings.

Details

The returned formats cover common separators ("/", "-", ".", " "), unseparated dates with numeric months, and an optional comma before a final 4- or 2-digit year element (%y, %Y) in space-separated dates.

Month handling depends on order:

  • If order uses "m", month tokens include numeric months (%m) and abbreviated month names (%b).

  • If order uses "M", month tokens include full month names (%B).

Month name formats (%b, %B) are locale-dependent.