Date conversion in R

r date-time format
convert factor to date in r
convert character to date in r lubridate
r convert number to date
r date format yyyymmdd
r date format mm/dd/yyyy
convert character to datetime in r
character to date in r na

I have a date column in the below format. I'm trying to extract day of the week. But it returns NA's.

df = data.frame(date=c("05-SEP-18", "10-SEP-18", "22-SEP-18"))
str(df)
'data.frame':   3 obs. of  1 variable:
 $ date: Factor w/ 3 levels "05-SEP-18","10-SEP-18",..: 1 2 3
df$day <- weekdays(as.Date(df$date, '%d-%M-%Y'))
head(df)
   date  day 
1 05-SEP-18 <NA>
2 10-SEP-18 <NA>
3 22-SEP-18 <NA>

I converted the factors to char. It still returns NA's

df$date <- as.character(df$date)
df$day <- weekdays(as.Date(df$date, '%d-%M-%Y'))
head(df)
date  day 1 05-SEP-18 <NA> 2 10-SEP-18 <NA> 3 22-SEP-18 <NA>

Any help please ?

Try as.Date(df$date, '%d-%b-%y'). %y% is two digit year. %b% is character abbreviated month.

https://www.google.com/amp/s/www.r-bloggers.com/date-formats-in-r/amp/

as.Date function, Date Conversion Functions to and from Character. Functions to convert between character representations and objects of class "Date" representing calendar� Importing DatesDates can be imported from character, numeric, POSIXlt, and POSIXct formats using the as.Date function from the base package.If your data were exported from Excel, they will possibly be in numeric format.

Try this with package lubridate:

library(lubridate)
df = data.frame(date = c("05-SEP-18", "10-SEP-18", "22-SEP-18"))
df$date <- as.Date(df$date)
#define timezone
lct <- Sys.getlocale("LC_TIME")
Sys.setlocale("LC_TIME", "C")
df$date <- as.Date(df$date, format = "%d-%b-%y")
wd <- weekdays(df$date)

Hope it help

Date Formats in R, Date function from the base package.If your data were. Date Formats in R. Posted by Mollie Conversion specification, Description, Example. Date Conversion Functions to and from Character Description. Functions to convert between character representations and objects of class "Date" representing calendar dates.

as mentioned above lubridate is an easy solution to parse the date and then use tidyverse to pipe together functions and create new columns:

  df %>% 
    mutate(date = dmy(date)) %>% 
    mutate(day  = weekdays(date))

        date       day
1 2018-09-05 Wednesday
2 2018-09-10    Monday
3 2018-09-22  Saturday

so while you can specify the date format manually, using functions such as dmy in lubridate simplifies this when the date is in a somewhat standard format.

Date Conversion Functions to and from Character, Functions to convert between character representations and objects of class " Date" representing calendar dates. Usage. as.Date(x, ) ## S3 method for class ' � If two times (using any of the date or date/time classes) are subtracted, R will return the results in the form of a time difference, which represents a difftime object. For example, New York City experienced a major blackout on July 13, 1997, and another on August 14, 2003.

Easily Converting Strings to Times and Dates in R with flipTime , Date conversion in R can be a real pain. However, it is a very important initial step when you first get your data into R to ensure that it has the correct type (e.g. � Date time conversion in R. Ask Question Asked 8 years, 4 months ago. Active 7 years, 6 months ago. Viewed 12k times 3. 1. I know similar things have been discussed

Dates and Times in R, date. Thus dates in R will generally have a numeric mode, and the class The as.numeric function can be used to convert a Date object to its� Hijri to Gregorian date converter converts Hijri dates into Gregorian dates via Hijri Date Converter & same for Gregorian to Hijri by IslamicFinder.org. IslamicFinder provides you with the most accurate Islamic Date Converter to facilitate you in your day to day planning.

Converting Date formats in R, To obtain your required format i.e., 2016-month-day , you can use format function once you have converted vector of strings to Date type. The as.Date methods return an object of class "Date". Note. The default formats follow the rules of the ISO 8601 international standard which expresses a day as "2001-02-03". If the date string does not specify the date completely, the returned answer may be system-specific.

Comments
  • Pretty sure that %Y is a four digit year. You have only two digits.
  • And %M is for numeric month. %b is abbreviated month.