I have a data.frame (CSV originally) in R with dates are in the following 3 formats:
2011-06-02T17:16:05Z
2012-06-02T17:16:05-07:00
6/2/11 17:16:05
which is year-month-day-time. I don't quite know what the -07:00 is, as it seems to be the same for all timestamps (except for some where it is -08:00), but I guess it's some type of time zone offset.
I am not quite sure what format these are (does anyone know?), but I need to convert it to this format:
6/2/11 17:16:05
which is year-month-day-time
I would like to do this in such a way so that all the dates in the CSV (in one and the same row) is converted to the second format. How can I accomplish this in R?
The full dataset can be found here.
Here's another attempt, assuming your data is text to start with:
test <- c("2011-06-02T17:16:05Z","2012-06-02T17:16:05-07:00")
format(as.POSIXct(test,format="%Y-%m-%dT17:%H:%M"),"%m/%d/%y %H:%M")
[1] "06/02/11 16:05" "06/02/12 16:05"
You can try the following, where myDates would be the column of dates
format(strptime(myDates, format="%Y-%m-%dT17:%H:%M"), format= "%m/%d/%Y %H:%M")
[1] "06/02/2011 16:05" "06/02/2012 16:05"
or with 2-digit year
# Note the lower-case %y at the end
format(strptime(myDates, format="%Y-%m-%dT17:%H:%M"), format= "%m/%d/%y %H:%M")
[1] "06/02/11 16:05" "06/02/12 16:05"
As for the Z, that indicates GMT (think: London).
the -7:00 indicates 7 hours back from GMT (think: Colorado / MST etc)
Please see here for more reference
Related
I obtained a time string looking like this:
201902041502, containing year, month, day, hour and minute.
Now I want to reformat this string into the german date-time format like this: 04.02.2019 15:02.
I've already tried as.Date and as.POSIXct but it doesnt work and I want to avoid adding seconds to get POSIXct to work.
Thanks in advance! Cheers
You can use strptime to convert the data to a POSIXlt object,
x <- "201902041502"
xd <- strptime(x,"%Y%m%d%H%M")
# [1] "2019-02-04 15:02:00 CET"
and then use strftime to produce your desired format:
strftime(xd, "%d.%m.%Y %H:%M")
# [1] "04.02.2019 15:02"
I have a table (tags) with a column for timestamp (ts), which is formatted as seconds since 1 Jan, 1970 GMT. I'm trying to create a date column that converts the timestamp from seconds to date and time EST.
The suggested code for R was:
tags$date<-strptime(tags$ts, "%Y-%m-%d")
tags$date<-as.POSIXct(tags$date)
But when I do this, tags$date comes up as NA. Any suggestions for what I might be doing wrong? Thanks.
You should us as.POSIXct function instead:
tags$date <- as.POSIXct(tags$ts, origin="1970-01-01", tz="US/New York")
strptime converts between character representations and dates not between timestamp and dates.
Here's a lubridate version. When we use as_datetime we don't need to explicitly specify an origin as it defaults to the desired origin.
lubridate::as_datetime(1507119276, tz='EST')
# [1] "2017-10-04 07:14:36 EST"
I'm having trouble formatting a list of dates in R. The conventional methods of formatting in R such as as.Date or as.POSIXct don't seem to be working.
I have dates in the format: 1012015
using
as.POSIXct(as.character(data$Start_Date), format = "%m%d%Y")
does not give me an error, but my date returns
"0015-10-12" because the month is not a two digit number.
Is there a way to change this into the correct date format?F
The lubridate package can help with this:
lubridate::mdy(1012015)
[1] "2015-01-01"
The format looks ambiguous but the OP gave two hints:
He is using format = "%m%d%Y" in his own attempt, and
he argues the issue is because the month is not a two digit number
This uses only base R. The %08d specifies a number to be formatted into 8 characters with 0 fill giving in this case "01012015".
as.POSIXct(sprintf("%08d", 1012015), format = "%m%d%Y")
## [1] "2015-01-01 EST"
Note that if you don't have any hours/minutes/seconds it would be less error prone to use "Date" class since then the possibility of subtle time zone errors is eliminated.
as.Date(sprintf("%08d", 1012015), format = "%m%d%Y")
## [1] "2015-01-01"
I'm importing time series data from a CSV file and one of the vectors/columns are dates in the format DD/MM/YYYY. Vector class is characters or factors if I chose the Strings as factors = True. I convert the imported file to a data frame and then run the following:
df$Date <- as.Date(df$Date , "%d/%m/%y")
I get no error message, but the dates are all messed up in the format YYYYMMDD and all the YYYY are the year 2020...
Before:
10/09/2009
11/09/2009
14/09/2009
After:
2020-09-10
2020-09-11
2020-09-14
You are using %y when it should be %Y. See the documentation here.
%y
Year without century (00–99). On input, values 00 to 68 are prefixed by 20 and 69 to 99 by 19 – that is the behaviour specified by the 2004 and 2008 POSIX standards, but they do also say ‘it is expected that in a future version the default century inferred from a 2-digit year will change’.
%Y
Year with century. Note that whereas there was no zero in the original Gregorian calendar, ISO 8601:2004 defines it to be valid (interpreted as 1BC): see http://en.wikipedia.org/wiki/0_(year). Note that the standards also say that years before 1582 in its calendar should only be used with agreement of the parties involved.
Try running the code again so that the data frame is not modified by any previous attempt but this time use
df$Date <- as.Date(df$Date , "%d/%m/%Y")
#Heroka is right.
If ever you need it you could also use posixct objects (they contain information of seconds)
Try this:
df$Date.time <- as.POSIXct(df$Date , format="%d/%m/%Y")
If you want the date and time in strings you can try the following:
df$Date.time <- format(as.POSIXct(df$Date , format="%d/%m/%Y"),format="%Y-%m-%d %H:%M")
or
df$Date <- format(as.POSIXct(df$Date , format="%d/%m/%Y"),format="%Y-%m-%d")
I have a file with nearly four thousand entries in a column formatted like this:
1/28/2015 14:13
How do I get R to read these as real numbers?
As #RomanLuštrik suggested:
mydate <- "1/28/2015 14:13"
# convert to date
strptime(mydate, "%m/%d/%Y %H:%M")
# [1] "2015-01-28 14:13:00 GMT"
# make it numeric
as.numeric(strptime(mydate, "%m/%d/%Y %H:%M"))
# [1] 1422454380
datestring<-"your variable"
x<-strptime(datestring, %b/%d,%Y %H:%M)
Just check out the strptime() info
there is the lubridate package with a lot of functions for this for changing formats
for real numbers you have POSIXct() function.