CODEWITHSUNDEEP
r
Vasile
Vasile

Reputation: 1017

Error transforming dates to days in r

I am adding a day-name column to a data frame that has a date column. Something like this:

date<-c ("01/09/2014", "24/08/2014", "28/08/2014")
id<-(1:3)
df<-data.frame(date,id)
df$day<-weekdays(as.Date(df$date))

However, the resulting column does not match the actual days. In the above example, for instance, September 1 is Thursday, while in reality it was a Monday. Thanks for your help.

Upvotes: 1

Views: 43

Answers (1)

Tim Biegeleisen
Tim Biegeleisen

Reputation: 521289

You need to specify the formatting when you call as.Date(). Try this code:

df$day <- weekdays(as.Date(df$date, format = "%d/%m/%Y"))

Be careful with the last formatting parameter. If you use lowercase y, %y, you will get the wrong answer.

> df
        date id      day
1 01/09/2014  1   Monday
2 24/08/2014  2   Sunday
3 28/08/2014  3 Thursday

Upvotes: 1

Related Questions