Package 'theRefdate'

Title: Simple and Fast Date Manipulation on Character Strings
Description: Provides simple and fast date manipulation functions operating on character strings in one of three formats: 'DD.MM.YYYY' (default), 'YYYY-MM-DD' or 'YYYYMMDD'. The format is chosen once per R session. Functions include extraction of day, month, and year components, computation of differences between two dates, and addition or subtraction of months. "DD" is ignored in the calculations, therefore a date like 31.02.2026 is a valid in- or output. That's why it is so fast.
Authors: Prem Lueers [aut, cre] (ORCID: <https://orcid.org/0009-0003-3315-1438>)
Maintainer: Prem Lueers <[email protected]>
License: LGPL-3
Version: 1.1.0
Built: 2026-10-16 15:01:29 UTC
Source: https://github.com/cran/theRefdate

Help Index

dateAddMonths

Description

Adds or subtracts a number of whole months to or from a date. The day is left unchanged.

Usage

dateAddMonths(termin, monthsToBeAdded, format = .zustand$name)

Arguments

termin

start date in the format of the flavour
monthsToBeAdded

number of whole months (positive: add, negative: subtract)
format

flavour; the default is the one set with setFlavour

Details

Invalid input, including NA and the empty string, is an error (version 1.0.0 returned NA).

Value

date in the format of the flavour

Examples

dateAddMonths("01.01.2000", -3 ) == "01.10.1999"

dateDiff

Description

Computes the difference between two dates in the format of the flavour. Returns the differences in years, months and total months as a named list.

Usage

dateDiff(frueher, spaeter, format = .zustand$name)

Arguments

frueher

earlier date in the format of the flavour
spaeter

later date in the format of the flavour
format

flavour; the default is the one set with setFlavour

Details

Invalid input, including NA and the empty string, is an error (version 1.0.0 returned NA).

Value

list with diffJ (years), diffM (months), diffDauer (duration in fractional years), diffDauerM (total months)

Examples

dateDiff("01.01.2000", "01.12.1999")$diffDauerM == -1

flavour

Description

Returns the active flavour (date format) of the package theRefdate.

Usage

flavour()

Value

character string: "dmy" (DD.MM.YYYY), "iso" (YYYY-MM-DD) or "iso_basic" (YYYYMMDD). The default is "dmy". Version 1.0.0 returned "LP" for this format.

Examples

flavour() == "dmy"

Function 'jahr'

Description

Extracts the year from a date string as 'numeric'.

Usage

jahr(datumstring, format = .zustand$name)

Arguments

datumstring

date string in the format of the flavour (default "DD.MM.YYYY")
format

flavour; the default is the one set with setFlavour

Details

Invalid input, including NA and the empty string, is an error (version 1.0.0 returned NA).

Value

numeric

Examples

jahr("02.02.2002") == 2002

Function 'monat'

Description

Extracts the month from a date string as 'numeric'.

Usage

monat(datumstring, format = .zustand$name)

Arguments

datumstring

date string in the format of the flavour (default "DD.MM.YYYY")
format

flavour; the default is the one set with setFlavour

Details

Invalid input, including NA and the empty string, is an error (version 1.0.0 returned NA).

Value

numeric

Examples

monat("02.02.2000") == 2

setFlavour

Description

Sets the flavour (date format) used by all functions of the package as long as they are called without their own argument format. The setting is valid for the whole R session. Changing it to a different flavour after it has been set once gives a warning. If setFlavour is never called, the package works in the format DD.MM.YYYY ("dmy") and returns the same results as version 1.0.0 for every valid input.

Usage

setFlavour(flavour)

Arguments

flavour

"dmy" (DD.MM.YYYY), "iso" (YYYY-MM-DD) or "iso_basic" (YYYYMMDD). The old identifiers "LP" (= dmy) and "VK" (= iso) are accepted as well.

Value

the flavour that was set (invisibly)

Examples

setFlavour( "iso" )
jahr( "2002-02-02" ) == 2002
setFlavour( "dmy" )

Function 'tag'

Description

Extracts the day from a date string as 'numeric'.

Usage

tag(datumstring, format = .zustand$name)

Arguments

datumstring

date string in the format of the flavour (default "DD.MM.YYYY")
format

flavour; the default is the one set with setFlavour

Details

Invalid input, including NA and the empty string, is an error (version 1.0.0 returned NA).

Value

numeric

Examples

tag("03.02.2000") == 3