impute_date: Impute Missing Components in Partial Date Strings

In datetoiso: Convert and Impute Dates to ISO Standard ("International Organization for Standardization")

Impute Missing Components in Partial Date Strings

Description

This function imputes missing **month** and/or **day** components in partial date strings where the **year** is known. It assumes input dates are provided in either the *dmy* format (day-month-year) **or** the *ymd* format (year-month-day) and does not process datetime values or strings containing time components or non-date characters.

Usage

impute_date(
  data_frame,
  column_name,
  date_format = "ymd",
  separator = "-",
  year = "UNKN",
  month = "UNK",
  day = "UN",
  min_max = "min",
  suffix = "_DT"
)

Arguments

data_frame	data frame
column_name	name of column that keeps dates to be imputed
date_format	by default "ymd". choose between ymd (if first year, then month then day) and dmy (if first day, then month then year)
separator	by default "-" it is a day-month-year separator, for example "2024-10-21" has "-" separator
year	by default "UNKN" - the format of unknown year
month	by default "UNK" - the format of unknown month
day	by default "UN" - the format of unknown day
min_max	by default "min". controlling imputation direction."min" - Impute the earliest possible date "max"' - Impute the latest possible date
suffix	by default "_DT" - new imputed date is named as source variable with suffix

Details

If the **year** is missing or explicitly marked as unknown (e.g., '"UNKN"'), the function returns 'NA'. When the **month** is missing, the function imputes **January (01)** as the default month. When the **day** is missing, it imputes the **first day of the month (01)**.

Any datetime strings (e.g., '"NA-01-2025T11:10:00"') must be preprocessed to remove the time component before applying this function (e.g., convert to '"NA-01-2025"').

In addition to imputing the date, the function creates an accompanying **flag variable** named as: '"<source_variable>_<suffix>F"'. This flag variable indicates the type of imputation performed:

• 'NA' — No imputation was performed (the original date was complete).

• '"D"' — The **day** component was imputed.

• '"M"' — The **month** component were imputed.

• '"D, M"' — Both **month** and **day** components were imputed.

Value

A data frame identical to the input, with an additional column representing the imputed values. The imputed column name is constructed by appending the suffix "_imputed" to the source variable name.

Author(s)

Lukasz Andrzejewski

Examples

impute_date(data_frame = data.frame(K = c('2025 11 UN', '2025 UNK 23')),
column_name = "K", separator = " ")

datetoiso documentation built on Dec. 7, 2025, 9:06 a.m.