When I try to parse a timestamp in the following format: "Thu Nov 8 15:41:45 2012", only NA is returned.
I am using Mac OS X, R 2.15.2 and Rstudio 0.97.237. The language of my OS is Dutch: I presume this has something to do with it.
When I try strptime, NA is returned:
var <- "Thu Nov 8 15:41:45 2012"
strptime(var, "%a %b %d %H:%M:%S %Y")
# [1] NA
Neither does as.POSIXct work:
as.POSIXct(var, "%a %b %d %H:%M:%S %Y")
# [1] NA
I also tried as.Date on the string above but without %H:%M:%S components:
as.Date("Thu Nov 8 2012", "%a %b %d %Y")
# [1] NA
Any ideas what I could be doing wrong?
I think it is exactly as you guessed, strptime fails to parse your date-time string because of your locales. Your string contains both abbreviated weekday (%a) and abbreviated month name (%b). These time specifications are described in ?strptime:
Details
%a: Abbreviated weekday name in the current locale on this
platform
%b: Abbreviated month name in the current locale on this platform.
"Note that abbreviated names are platform-specific (although the
standards specify that in the C locale they must be the first three
letters of the capitalized English name:"
"Knowing what the abbreviations are is essential if you wish to use
%a, %b or %h as part of an input format: see the examples for
how to check."
See also
[...] locales to query or set a locale.
The issue of locales is relevant also for as.POSIXct, as.POSIXlt and as.Date.
From ?as.POSIXct:
Details
If format is specified, remember that some of the format
specifications are locale-specific, and you may need to set the
LC_TIME category appropriately via Sys.setlocale. This most often
affects the use of %b, %B (month names) and %p (AM/PM).
From ?as.Date:
Details
Locale-specific conversions to and from character strings are used
where appropriate and available. This affects the names of the days
and months.
Thus, if weekdays and month names in the string differ from those in the current locale, strptime, as.POSIXct and as.Date fail to parse the string correctly and NA is returned.
However, you may solve this issue by changing the locales:
# First save your current locale
loc <- Sys.getlocale("LC_TIME")
# Set correct locale for the strings to be parsed
# (in this particular case: English)
# so that weekdays (e.g "Thu") and abbreviated month (e.g "Nov") are recognized
Sys.setlocale("LC_TIME", "en_GB.UTF-8")
# or
Sys.setlocale("LC_TIME", "C")
#Then proceed as you intended
x <- "Thu Nov 8 15:41:45 2012"
strptime(x, "%a %b %d %H:%M:%S %Y")
# [1] "2012-11-08 15:41:45"
# Then set back to your old locale
Sys.setlocale("LC_TIME", loc)
With my personal locale I can reproduce your error:
Sys.setlocale("LC_TIME", loc)
# [1] "fr_FR.UTF-8"
strptime(var,"%a %b %d %H:%M:%S %Y")
# [1] NA
Was just messing around with same problem, and found this solution to be much cleaner because there is no need to change any of system settings manually, because there is a wrapper function doing this job in the lubridate package, and all you have to do is set the argument locale:
date <- c("23. juni 2014", "1. november 2014", "8. marts 2014", "16. juni 2014", "12. december 2014", "13. august 2014")
df$date <- dmy(df$Date, locale = "Danish")
[1] "2014-06-23" "2014-11-01" "2014-03-08" "2014-06-16" "2014-12-12" "2014-08-13"
Related
I have a data file that has timezone info in the datetime field. It looks something like this
"Wed May 18 13:42:29 MDT 2016"
I'm trying to convert this to a POSIXct object. Unfortunately %Z is allowed only for output. For eg.
> timestr <- "Wed May 18 13:42:29 MDT 2016"
> tm.posixct <- as.POSIXct(timestr, tz="US/Mountain", format = "%a %b %d %H:%M:%S MDT %Y")
My data file contains MDT or MST, hence I can't use that in the format string. Is there anyway to use the TZ info in that timefield for conversion instead of doing string manipulation and removing the timezone info before passing it to as.POSIXct?
When I try to parse a timestamp in the following format: "Thu Nov 8 15:41:45 2012", only NA is returned.
I am using Mac OS X, R 2.15.2 and Rstudio 0.97.237. The language of my OS is Dutch: I presume this has something to do with it.
When I try strptime, NA is returned:
var <- "Thu Nov 8 15:41:45 2012"
strptime(var, "%a %b %d %H:%M:%S %Y")
# [1] NA
Neither does as.POSIXct work:
as.POSIXct(var, "%a %b %d %H:%M:%S %Y")
# [1] NA
I also tried as.Date on the string above but without %H:%M:%S components:
as.Date("Thu Nov 8 2012", "%a %b %d %Y")
# [1] NA
Any ideas what I could be doing wrong?
I think it is exactly as you guessed, strptime fails to parse your date-time string because of your locales. Your string contains both abbreviated weekday (%a) and abbreviated month name (%b). These time specifications are described in ?strptime:
Details
%a: Abbreviated weekday name in the current locale on this
platform
%b: Abbreviated month name in the current locale on this platform.
"Note that abbreviated names are platform-specific (although the
standards specify that in the C locale they must be the first three
letters of the capitalized English name:"
"Knowing what the abbreviations are is essential if you wish to use
%a, %b or %h as part of an input format: see the examples for
how to check."
See also
[...] locales to query or set a locale.
The issue of locales is relevant also for as.POSIXct, as.POSIXlt and as.Date.
From ?as.POSIXct:
Details
If format is specified, remember that some of the format
specifications are locale-specific, and you may need to set the
LC_TIME category appropriately via Sys.setlocale. This most often
affects the use of %b, %B (month names) and %p (AM/PM).
From ?as.Date:
Details
Locale-specific conversions to and from character strings are used
where appropriate and available. This affects the names of the days
and months.
Thus, if weekdays and month names in the string differ from those in the current locale, strptime, as.POSIXct and as.Date fail to parse the string correctly and NA is returned.
However, you may solve this issue by changing the locales:
# First save your current locale
loc <- Sys.getlocale("LC_TIME")
# Set correct locale for the strings to be parsed
# (in this particular case: English)
# so that weekdays (e.g "Thu") and abbreviated month (e.g "Nov") are recognized
Sys.setlocale("LC_TIME", "en_GB.UTF-8")
# or
Sys.setlocale("LC_TIME", "C")
#Then proceed as you intended
x <- "Thu Nov 8 15:41:45 2012"
strptime(x, "%a %b %d %H:%M:%S %Y")
# [1] "2012-11-08 15:41:45"
# Then set back to your old locale
Sys.setlocale("LC_TIME", loc)
With my personal locale I can reproduce your error:
Sys.setlocale("LC_TIME", loc)
# [1] "fr_FR.UTF-8"
strptime(var,"%a %b %d %H:%M:%S %Y")
# [1] NA
Was just messing around with same problem, and found this solution to be much cleaner because there is no need to change any of system settings manually, because there is a wrapper function doing this job in the lubridate package, and all you have to do is set the argument locale:
date <- c("23. juni 2014", "1. november 2014", "8. marts 2014", "16. juni 2014", "12. december 2014", "13. august 2014")
df$date <- dmy(df$Date, locale = "Danish")
[1] "2014-06-23" "2014-11-01" "2014-03-08" "2014-06-16" "2014-12-12" "2014-08-13"
When I try to parse a timestamp in the following format: "Thu Nov 8 15:41:45 2012", only NA is returned.
I am using Mac OS X, R 2.15.2 and Rstudio 0.97.237. The language of my OS is Dutch: I presume this has something to do with it.
When I try strptime, NA is returned:
var <- "Thu Nov 8 15:41:45 2012"
strptime(var, "%a %b %d %H:%M:%S %Y")
# [1] NA
Neither does as.POSIXct work:
as.POSIXct(var, "%a %b %d %H:%M:%S %Y")
# [1] NA
I also tried as.Date on the string above but without %H:%M:%S components:
as.Date("Thu Nov 8 2012", "%a %b %d %Y")
# [1] NA
Any ideas what I could be doing wrong?
I think it is exactly as you guessed, strptime fails to parse your date-time string because of your locales. Your string contains both abbreviated weekday (%a) and abbreviated month name (%b). These time specifications are described in ?strptime:
Details
%a: Abbreviated weekday name in the current locale on this
platform
%b: Abbreviated month name in the current locale on this platform.
"Note that abbreviated names are platform-specific (although the
standards specify that in the C locale they must be the first three
letters of the capitalized English name:"
"Knowing what the abbreviations are is essential if you wish to use
%a, %b or %h as part of an input format: see the examples for
how to check."
See also
[...] locales to query or set a locale.
The issue of locales is relevant also for as.POSIXct, as.POSIXlt and as.Date.
From ?as.POSIXct:
Details
If format is specified, remember that some of the format
specifications are locale-specific, and you may need to set the
LC_TIME category appropriately via Sys.setlocale. This most often
affects the use of %b, %B (month names) and %p (AM/PM).
From ?as.Date:
Details
Locale-specific conversions to and from character strings are used
where appropriate and available. This affects the names of the days
and months.
Thus, if weekdays and month names in the string differ from those in the current locale, strptime, as.POSIXct and as.Date fail to parse the string correctly and NA is returned.
However, you may solve this issue by changing the locales:
# First save your current locale
loc <- Sys.getlocale("LC_TIME")
# Set correct locale for the strings to be parsed
# (in this particular case: English)
# so that weekdays (e.g "Thu") and abbreviated month (e.g "Nov") are recognized
Sys.setlocale("LC_TIME", "en_GB.UTF-8")
# or
Sys.setlocale("LC_TIME", "C")
#Then proceed as you intended
x <- "Thu Nov 8 15:41:45 2012"
strptime(x, "%a %b %d %H:%M:%S %Y")
# [1] "2012-11-08 15:41:45"
# Then set back to your old locale
Sys.setlocale("LC_TIME", loc)
With my personal locale I can reproduce your error:
Sys.setlocale("LC_TIME", loc)
# [1] "fr_FR.UTF-8"
strptime(var,"%a %b %d %H:%M:%S %Y")
# [1] NA
Was just messing around with same problem, and found this solution to be much cleaner because there is no need to change any of system settings manually, because there is a wrapper function doing this job in the lubridate package, and all you have to do is set the argument locale:
date <- c("23. juni 2014", "1. november 2014", "8. marts 2014", "16. juni 2014", "12. december 2014", "13. august 2014")
df$date <- dmy(df$Date, locale = "Danish")
[1] "2014-06-23" "2014-11-01" "2014-03-08" "2014-06-16" "2014-12-12" "2014-08-13"
When I try to parse a timestamp in the following format: "Thu Nov 8 15:41:45 2012", only NA is returned.
I am using Mac OS X, R 2.15.2 and Rstudio 0.97.237. The language of my OS is Dutch: I presume this has something to do with it.
When I try strptime, NA is returned:
var <- "Thu Nov 8 15:41:45 2012"
strptime(var, "%a %b %d %H:%M:%S %Y")
# [1] NA
Neither does as.POSIXct work:
as.POSIXct(var, "%a %b %d %H:%M:%S %Y")
# [1] NA
I also tried as.Date on the string above but without %H:%M:%S components:
as.Date("Thu Nov 8 2012", "%a %b %d %Y")
# [1] NA
Any ideas what I could be doing wrong?
I think it is exactly as you guessed, strptime fails to parse your date-time string because of your locales. Your string contains both abbreviated weekday (%a) and abbreviated month name (%b). These time specifications are described in ?strptime:
Details
%a: Abbreviated weekday name in the current locale on this
platform
%b: Abbreviated month name in the current locale on this platform.
"Note that abbreviated names are platform-specific (although the
standards specify that in the C locale they must be the first three
letters of the capitalized English name:"
"Knowing what the abbreviations are is essential if you wish to use
%a, %b or %h as part of an input format: see the examples for
how to check."
See also
[...] locales to query or set a locale.
The issue of locales is relevant also for as.POSIXct, as.POSIXlt and as.Date.
From ?as.POSIXct:
Details
If format is specified, remember that some of the format
specifications are locale-specific, and you may need to set the
LC_TIME category appropriately via Sys.setlocale. This most often
affects the use of %b, %B (month names) and %p (AM/PM).
From ?as.Date:
Details
Locale-specific conversions to and from character strings are used
where appropriate and available. This affects the names of the days
and months.
Thus, if weekdays and month names in the string differ from those in the current locale, strptime, as.POSIXct and as.Date fail to parse the string correctly and NA is returned.
However, you may solve this issue by changing the locales:
# First save your current locale
loc <- Sys.getlocale("LC_TIME")
# Set correct locale for the strings to be parsed
# (in this particular case: English)
# so that weekdays (e.g "Thu") and abbreviated month (e.g "Nov") are recognized
Sys.setlocale("LC_TIME", "en_GB.UTF-8")
# or
Sys.setlocale("LC_TIME", "C")
#Then proceed as you intended
x <- "Thu Nov 8 15:41:45 2012"
strptime(x, "%a %b %d %H:%M:%S %Y")
# [1] "2012-11-08 15:41:45"
# Then set back to your old locale
Sys.setlocale("LC_TIME", loc)
With my personal locale I can reproduce your error:
Sys.setlocale("LC_TIME", loc)
# [1] "fr_FR.UTF-8"
strptime(var,"%a %b %d %H:%M:%S %Y")
# [1] NA
Was just messing around with same problem, and found this solution to be much cleaner because there is no need to change any of system settings manually, because there is a wrapper function doing this job in the lubridate package, and all you have to do is set the argument locale:
date <- c("23. juni 2014", "1. november 2014", "8. marts 2014", "16. juni 2014", "12. december 2014", "13. august 2014")
df$date <- dmy(df$Date, locale = "Danish")
[1] "2014-06-23" "2014-11-01" "2014-03-08" "2014-06-16" "2014-12-12" "2014-08-13"
In a data.frame, I have a date time stamp in the form:
head(x$time)
[1] "Thu Oct 11 22:18:02 2012" "Thu Oct 11 22:50:15 2012" "Thu Oct 11 22:54:17 2012"
[4] "Thu Oct 11 22:43:13 2012" "Thu Oct 11 22:41:18 2012" "Thu Oct 11 22:15:19 2012"
Everytime I try to convert it with as.Date, lubridate, or zoo I get NAs or Errors.
What is the way to convert this time to a readable form?
I've tried:
Time<-strptime(x$time,format="&m/%d/%Y %H:$M")
x$minute<-parse_date_time(x$time)
x$minute<-mdy(x$time)
x$minute<-as.Date(x$time,"%m/%d/%Y %H:%M:%S")
x$minute<-as.time(x$time)
x$minute<-as.POSIXct(x$time,format="%H:%M")
x$minute<-minute(x$time)
What you really want is strptime(). Try something like:
strptime(x$time, "%a %b %d %H:%M:%S %Y")
As an example of the interesting things you can do with strptime(), consider the following:
thedate <- "I came to your house at 11:45 on January 21, 2012."
strptime(thedate, "I came to your house at %H:%M on %B %d, %Y.")
# [1] "2012-01-21 11:45:00"
Another option is to use lubridate::parse_date_time():
library(lubridate)
parse_date_time(x$time, "%a %b %d %H:%M:%S %Y")
Or more simply:
parse_date_time(x$time, "abdHMSY")
From the docs:
It differs from base::strptime() in two respects. First, it allows specification of the order in which the formats occur without the need to include separators and % prefix. Such a formating argument is refered to as "order". Second, it allows the user to specify several format-orders to handle heterogeneous date-time character representations.
The docs contain all the formats (the "abdHMSY" etc.) recognized by lubridate.