Hi,
Let say I have a date variable like this:
structure(1243792800, class = c("POSIXct", "POSIXt"), tzone = "GMT")
[1] "2009-05-31 18:00:00 GMT"
How can I make it 10 days prior, so:
[1] "2009-05-21 18:00:00 GMT"
I'm randomly selecting dates from a list and want a second value a set #
of days either before or after.
Thanks ahead of time.
--
View this message in context: http://r.789695.n4.nabble.com/changing-date-by-days-tp4647803.html
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changing date by +/- days
4 messages · chuck.01, Jeff Newmiller, arun
got it, sorry!
structure(1243792800, class = c("POSIXct", "POSIXt"), tzone =
"GMT")-(60*60*24*10)
chuck.01 wrote
Hi,
Let say I have a date variable like this:
structure(1243792800, class = c("POSIXct", "POSIXt"), tzone = "GMT")
[1] "2009-05-31 18:00:00 GMT"
How can I make it 10 days prior, so:
[1] "2009-05-21 18:00:00 GMT"
I'm randomly selecting dates from a list and want a second value a set #
of days either before or after.
Thanks ahead of time.
-- View this message in context: http://r.789695.n4.nabble.com/changing-date-by-days-tp4647803p4647804.html Sent from the R help mailing list archive at Nabble.com.
I try to use difftimes as much as possible. For example,
oneday <- as.difftime( 24, units="hours" )
sometime - 10 * oneday
You might also find the lubridate package useful.
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"chuck.01" <CharlieTheBrown77 at gmail.com> wrote:
got it, sorry!
structure(1243792800, class = c("POSIXct", "POSIXt"), tzone =
"GMT")-(60*60*24*10)
chuck.01 wrote
Hi,
Let say I have a date variable like this:
structure(1243792800, class = c("POSIXct", "POSIXt"), tzone = "GMT")
[1] "2009-05-31 18:00:00 GMT"
How can I make it 10 days prior, so:
[1] "2009-05-21 18:00:00 GMT"
I'm randomly selecting dates from a list and want a second value a
set #
of days either before or after. Thanks ahead of time.
-- View this message in context: http://r.789695.n4.nabble.com/changing-date-by-days-tp4647803p4647804.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Hi,
Try this:
dat1<-structure(1243792800, class = c("POSIXct", "POSIXt"), tzone = "GMT")
?dat2<-as.POSIXlt(dat1)
?dat2$mday<-dat2$mday-10
?dat2
#[1] "2009-05-21 18:00:00 GMT"
A.K.
----- Original Message -----
From: chuck.01 <CharlieTheBrown77 at gmail.com>
To: r-help at r-project.org
Cc:
Sent: Monday, October 29, 2012 8:37 PM
Subject: [R] changing date by +/- days
Hi,
Let say I have a date variable like this:
structure(1243792800, class = c("POSIXct", "POSIXt"), tzone = "GMT")
[1] "2009-05-31 18:00:00 GMT"
How can I make it 10 days prior, so:
[1] "2009-05-21 18:00:00 GMT"
I'm randomly selecting dates from a list? and want a? second value a set #
of days either before or after.
Thanks ahead of time.
--
View this message in context: http://r.789695.n4.nabble.com/changing-date-by-days-tp4647803.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.