date_tweaks: Combine vector to create Date, or split Date into vector

In quickcode: Quick and Essential 'R' Tricks for Better Scripts

Combine vector to create Date, or split Date into vector

Description

Combine or split Date into a specified format

Usage

date3to1(data, out.format = "%Y-%m-%d", col.YMD = 1:3, as.vector = FALSE)

date1to3(
  data,
  in.format = "%Y-%m-%d",
  date.col = 1,
  out.cols = c("%Y", "%m", "%d")
)

Arguments

data	data frame object
out.format	date output format
col.YMD	columns to combine for Year, Month and Day
as.vector	return output as vector, or leave as data frame
in.format	date input format
date.col	numeric value of column within the dataset that contains the dates
out.cols	cols to of date items to split. Make sure to conform to date formats. See "NOTE" section for date formats

Details

NOTE for date3to1

The three input columns corresponding to "Year Month Day" must be numeric values.

For example, Do not provide the month variable as non-numeric such as "Mar", "Jul", or "Jan".

If the values of the columns are non-numeric, the results will return an "NA" in the output.date column.

Value

date derived from combining values from three columns of a data frame

Note

DATE FORMATS IN R

Date Specification		Description		Example
%a		Abbreviated weekday		Sun, Thu
%A		Full weekday		Sunday
%b		Abbreviated month		May, Jul
%B		Full month		March, July
%d		Day of the month		27, 07
%j		Day of the year		148, 188
%m		Month		05, 07
%U		Week, with Sunday as first day		22, 27
%w		Weekday, Sunday is 0		0, 4
%W		Week, with Monday as first day		21, 27
%x		Date, locale-specific
%y		Year without century		84, 05
%Y		Year with century		1984, 2005
%C		Century		19, 20
%D		Date formatted %m/%d/%y		07/17/23
%u		Weekday, Monday is 1		7, 4

References

Adapted from Ecfun R package

Examples

# EXAMPLES FOR date3to1

data0 <- data.frame(y=c(NA, -1, 2001:2009),
m=c(1:2, -1, NA, 13, 2, 12, 6:9),
d=c(0, 0:6, NA, -1, 32) )
head(data0)

# combine and convert to date
# return as data frame
date3to1(data0)

# combine and convert to date
# return as vector
date3to1(data0, as.vector = TRUE) #eg. 2004-02-04


# combine and convert to date in the format DD_MM_YYYY
date3to1(data0, out.format = "%d_%m_%Y") #eg. 04_02_1974


# combine and convert to date in the format MM_DD_YY
date3to1(data0, out.format = "%m_%d_%y") #eg. 02_04_74

# combine and convert to date in the various date formats
date3to1(data0, out.format = "%B %d, %y") #eg. February 04, 74
date3to1(data0, out.format = "%a, %b %d, %Y") #eg. Mon, Feb 04, 1974
date3to1(data0, out.format = "%A, %B %d, %Y") #eg. Monday, February 04, 1974
date3to1(data0, out.format = "Day %j in Year %Y") #eg. Day 035 in Year 1974
date3to1(data0, out.format = "Week %U in %Y") #eg. Week 05 in 1974
date3to1(data0, out.format = "Numeric month %m in Year %Y") #eg. Numeric month 02 in Year 1974





# EXAMPLES FOR date1to3

data1 <- data.frame(Full.Dates =
                      c("2023-02-14",NA,NA,
                        "2002-12-04","1974-08-04",
                        "2008-11-10"))
head(data1)

# split date with default settings
# return as data frame with columns
# for day(d), month(m) and year(Y)
date1to3(data1)


# split date in the format and only return year in YYYY
date1to3(data1, out.cols = "%Y") #eg. 2002, 2023


# split date in the format and only return month in m
date1to3(data1, out.cols = "%m") #eg. 02, 12, 08

# split date in the format and return multiple date formats colums
date1to3(data1, out.cols = c("%B","%d") )
date1to3(data1, out.cols = c("%a","%b","%y") )
date1to3(data1, out.cols = c("%A","%B","%Y","%y") )
date1to3(data1, out.cols = c("%j","%Y","%y","%m") )
date1to3(data1, out.cols = c("%U","%Y","%y","%x") )
date1to3(data1, out.cols = c("%m","%Y","%y","%C") )

quickcode documentation built on April 11, 2025, 5:49 p.m.