date conversion problem

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date conversion problem

fipoucat
I have dataset with time sine 1800-01-01 and extracted data from 1981 to
2019 and used these lines for the data conversion:
> time_d <- as.Date(time, format="%j", origin=as.Date("1800-01-01"))
> time_years <- format(time_d, "%Y")
> time_months <- format(time_d, "%m")
> time_year_months <- format(time_d, "%Y-%m")
> head(time_d)
[1] "6095-12-22" "6096-01-15" "6096-02-08" "6096-03-03" "6096-03-27"
"6096-04-20"

As you see these gregorian dates are unrealistic and wonder what I am doing
wrong?
The time from the raw file in Jd are like this:

> time
   [1] 1569072 1569096 1569120 1569144 1569168 1569192 1569216 1569240etc.

Hope hint and/or suggestion to solve this.

Best regards

        [[alternative HTML version deleted]]

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Re: date conversion problem

Jim Lemon-4
Hi Abdoulaye,
It looks to me as though your offsets are in hours, not days. You can
get a rough date like this:

time<-c(1569072,1569096,1569120,1569144,
 1569168,1569192,1569216,1569240)
time_d<-as.Date("1800-01-01")+time/24
time_d
[1] "1979-01-01" "1979-01-02" "1979-01-03" "1979-01-04" "1979-01-05"
[6] "1979-01-06" "1979-01-07" "1979-01-08"

Jim

On Thu, Aug 13, 2020 at 6:10 PM Abdoulaye Sarr <[hidden email]> wrote:

>
> I have dataset with time sine 1800-01-01 and extracted data from 1981 to
> 2019 and used these lines for the data conversion:
> > time_d <- as.Date(time, format="%j", origin=as.Date("1800-01-01"))
> > time_years <- format(time_d, "%Y")
> > time_months <- format(time_d, "%m")
> > time_year_months <- format(time_d, "%Y-%m")
> > head(time_d)
> [1] "6095-12-22" "6096-01-15" "6096-02-08" "6096-03-03" "6096-03-27"
> "6096-04-20"
>
> As you see these gregorian dates are unrealistic and wonder what I am doing
> wrong?
> The time from the raw file in Jd are like this:
>
> > time
>    [1] 1569072 1569096 1569120 1569144 1569168 1569192 1569216 1569240etc.
>
> Hope hint and/or suggestion to solve this.
>
> Best regards
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] mailing list -- To UNSUBSCRIBE and more, see
> 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.

______________________________________________
[hidden email] mailing list -- To UNSUBSCRIBE and more, see
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.
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Re: date conversion problem

fipoucat
Hi Jim,

Thanks for the hint, that makes sense and I'll arrange accordingly.
Best regards,
Abdoulaye

On Thu, Aug 13, 2020 at 8:38 AM Jim Lemon <[hidden email]> wrote:

> Hi Abdoulaye,
> It looks to me as though your offsets are in hours, not days. You can
> get a rough date like this:
>
> time<-c(1569072,1569096,1569120,1569144,
>  1569168,1569192,1569216,1569240)
> time_d<-as.Date("1800-01-01")+time/24
> time_d
> [1] "1979-01-01" "1979-01-02" "1979-01-03" "1979-01-04" "1979-01-05"
> [6] "1979-01-06" "1979-01-07" "1979-01-08"
>
> Jim
>
> On Thu, Aug 13, 2020 at 6:10 PM Abdoulaye Sarr <[hidden email]>
> wrote:
> >
> > I have dataset with time sine 1800-01-01 and extracted data from 1981 to
> > 2019 and used these lines for the data conversion:
> > > time_d <- as.Date(time, format="%j", origin=as.Date("1800-01-01"))
> > > time_years <- format(time_d, "%Y")
> > > time_months <- format(time_d, "%m")
> > > time_year_months <- format(time_d, "%Y-%m")
> > > head(time_d)
> > [1] "6095-12-22" "6096-01-15" "6096-02-08" "6096-03-03" "6096-03-27"
> > "6096-04-20"
> >
> > As you see these gregorian dates are unrealistic and wonder what I am
> doing
> > wrong?
> > The time from the raw file in Jd are like this:
> >
> > > time
> >    [1] 1569072 1569096 1569120 1569144 1569168 1569192 1569216
> 1569240etc.
> >
> > Hope hint and/or suggestion to solve this.
> >
> > Best regards
> >
> >         [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > [hidden email] mailing list -- To UNSUBSCRIBE and more, see
> > 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.
>

        [[alternative HTML version deleted]]

______________________________________________
[hidden email] mailing list -- To UNSUBSCRIBE and more, see
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.