Date Time in R

readLines("YourCSVfilename.csv", n=5)

Hi,

That eir$date might be a factor is irrelevant. There is an as.Date()
method for factors, which does the factor to character coercion internally
and then calls as.Date.character() on the result.

Using the example data below:

eir <- data.frame(date = c("05-30-16", "05-30-16", "05-30-16",
                           "05-30-16", "05-30-16", "05-30-16"))

str(eir)

'data.frame':   6 obs. of  1 variable:
 $ date: Factor w/ 1 level "05-30-16": 1 1 1 1 1 1

eir

      date
1 05-30-16
2 05-30-16
3 05-30-16
4 05-30-16
5 05-30-16
6 05-30-16

eir$date <- as.Date(eir$date, format = "%m-%d-%y")

str(eir)

'data.frame':   6 obs. of  1 variable:
 $ date: Date, format: "2016-05-30" ...

eir

        date
1 2016-05-30
2 2016-05-30
3 2016-05-30
4 2016-05-30
5 2016-05-30
6 2016-05-30

eir$days <- weekdays(eir$date)

str(eir)

'data.frame':   6 obs. of  2 variables:
 $ date: Date, format: "2016-05-30" ...
 $ days: chr  "Monday" "Monday" "Monday" "Monday" ...

eir

        date   days
1 2016-05-30 Monday
2 2016-05-30 Monday
3 2016-05-30 Monday
4 2016-05-30 Monday
5 2016-05-30 Monday
6 2016-05-30 Monday


I would check to be sure that you do not have any typos in your code.

Regards,

Marc Schwartz

On Jul 26, 2016, at 6:58 AM, Shivi Bhatia <shivipmp82 at gmail.com> wrote:

Hello Again,

While i tried your solution as you suggested above it seems to be

working.

Here is the output
temp<- dput(head(eir$date))
c("05-30-16", "05-30-16", "05-30-16", "05-30-16", "05-30-16", "05-30-16")
however it still shows class(eir$date) as character and hence i cannot

find

weekdays from this variable.

Sorry but i still dont understand in totality how R reads dates even

though

have tried enough.

Regards, Shivi


On Tue, Jul 26, 2016 at 5:12 PM, Shivi Bhatia <shivipmp82 at gmail.com>

wrote:

Thanks Duncan for the quick response. I will check again as you

suggested.

If that doesn't work i will share a reproducible example.

Thanks again!!!!

On Tue, Jul 26, 2016 at 4:43 PM, Duncan Murdoch <

murdoch.duncan at gmail.com>

wrote:

On 26/07/2016 7:05 AM, Shivi Bhatia wrote:

Hi Team,

This scenario may have come across a number of times however i checked
nabble & SO and couldn't find a solution hence request assistance.

I have a date variable in my data-set eir. The class of this var was
character while i had read the file in r studio. Example of date -
05-30-16

To change this i have used eir$date<- as.Date(eir$date, "%m-%d-%y").

This

converts it to a date variable. However when i check few obs
with head(eir$date) all the results are <NA>.

I think you don't have character data like that, because I see

as.Date("05-30-16", "%m-%d-%y")

[1] "2016-05-30"

I'd guess eir$date is really a factor, because character data is
frequently changed to factor automatically.  If that's the case, this
should work for the conversion:

as.Date(as.character(eir$date), "%m-%d-%y")

If that doesn't work, you'll need to post something reproducible.

Duncan Murdoch

I also need to create weekdays from this date variable but until i get

this
resolved i cant find a weekday. For weekday i have used:
eir$week<- (eir$date)
eir$week<- weekdays(as.Date(eir$week))
class(eir$week)
eir$week<- as.factor(eir$week)
head(eir$week)

Head of this eir$week results again as expected in <NA> but shows

Levels:

Friday Monday Saturday Sunday Thursday Tuesday Wednesday

Not sure what i should do here. Kindly suggest.