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Guess if a character vector contains Date values, and convert them to date

Source: R/date_standardization_helpers.R
date_guess_convert.Rd

Guess if a character vector contains Date values, and convert them to date

Usage

date_guess_convert(data, error_tolerance, timeframe, orders, modern_excel)

Arguments

data

A data frame

error_tolerance

A number between 0 and 1 indicating the proportion of entries which cannot be identified as dates to be tolerated; if this proportion is exceeded, the original vector is returned, and a message is issued; defaults to 0.4 (40 percent).

timeframe

A vector of 2 values of type date. If provided, date values that do not fall within this timeframe will be set to NA.

orders

The date codes for fine-grained parsing of dates. This allows for parsing of mixed dates. If a list is supplied, that list will be used for successive tries in parsing. Default orders are:

list(
  world_named_months = c("Ybd", "dby"),
  world_digit_months = c("dmy", "Ymd"),
  US_formats         = c("Omdy", "YOmd")
)

modern_excel

When parsing dates from excel, some dates are stored as integers. Modern versions of Excel represent dates as the number of days since 1900-01-01, but pre-2011 Excel for OSX have the origin set at 1904-01-01. If this parameter is TRUE (default), then this assumes that all numeric values represent dates from either a Windows version of Excel or a 2011 or later version of Excel for OSX. Set this parameter to FALSE if the data came from an OSX version of Excel before 2011.

Value

The input data frame where the character columns with date values have been converted into Date.