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Luigi Marongiu

2021-Dec-14 10:54 UTC

[R] Format dates issues with R

Hello,
I have these kind of dates:
```> ori[[n[3]]][1] "9/20/2021" "9/20/2021" "9/20/2021"
"9/20/2021" "9/20/2021" "9/20/2021"
[7] "9/20/2021" "9/20/2021" "9/20/2021"
"9/20/2021" "9/21/2021" "9/21/2021"
[13] "9/21/2021" "9/21/2021" "9/21/2021"
"9/21/2021" "9/21/2021" "9/21/2021"
[19] "9/21/2021" "9/21/2021" "9/22/2021"
"9/22/2021" "9/22/2021" "9/22/2021"
[25] "9/22/2021" "9/22/2021" "9/22/2021"
"9/22/2021" "9/22/2021" "9/22/2021"
[31] "9/23/2021" "9/23/2021" "9/23/2021"
"9/23/2021" "9/23/2021" "9/23/2021"
[37] "9/23/2021" "9/23/2021" "9/23/2021"
"9/23/2021" "9/24/2021" "9/24/2021"
[43] "9/24/2021" "9/24/2021" "9/24/2021"
"9/24/2021" "9/24/2021" "9/24/2021"
[49] "9/24/2021" "9/24/2021" "9/27/2021"
"9/27/2021" "9/27/2021" "9/27/2021"
[55] "9/27/2021" "9/27/2021" "9/27/2021"
"9/27/2021" "9/27/2021" "9/27/2021"
[61] "9/28/2021" "9/28/2021" "9/28/2021"
"9/28/2021" "9/28/2021" "9/28/2021"
[67] "9/28/2021" "9/28/2021" "9/28/2021"
"9/28/2021" "9/29/2021" "9/29/2021"
[73] "9/29/2021" "9/29/2021" "9/29/2021"
"9/29/2021" "9/29/2021" "9/29/2021"
[79] "9/29/2021" "9/29/2021" "10/1/2021"
"10/1/2021"
```
they look to me as month, date, year so I formatted them as:
```> as.Date(ori[[n[3]]], format = "%D")# or:  as.Date(ori[[n[3]]], format = "%d/%m/%y")
[1] NA           NA           NA           NA           NA
NA
[7] NA           NA           NA           NA           NA
NA
[13] NA           NA           NA           NA           NA
NA
[19] NA           NA           NA           NA           NA
NA
[25] NA           NA           NA           NA           NA
NA
[31] NA           NA           NA           NA           NA
NA
[37] NA           NA           NA           NA           NA
NA
[43] NA           NA           NA           NA           NA
NA
[49] NA           NA           NA           NA           NA
NA
[55] NA           NA           NA           NA           NA
NA
[61] NA           NA           NA           NA           NA
NA
[67] NA           NA           NA           NA           NA
NA
[73] NA           NA           NA           NA           NA
NA
[79] NA           NA           "2010-01-20" "2010-01-20"
```
Why the conversion did not work?
Thank you

Ivan Krylov

2021-Dec-14 10:59 UTC

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[R] Format dates issues with R

On Tue, 14 Dec 2021 11:54:08 +0100
Luigi Marongiu <marongiu.luigi at gmail.com> wrote:
> "9/29/2021"
> format = "%d/%m/%y"
> Why the conversion did not work?
The according to the format, the date above is 9th of month No. 29 in
the year 2020, followed by junk characters "21". Swap %m and %d to
make
them follow the actual order and use %Y to parse the 4-digit year
instead of 2-digit year.

-- 
Best regards,
Ivan

Ivan Calandra

2021-Dec-14 10:59 UTC

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[R] Format dates issues with R

Dear Luigi,

Quickly, I spot two problems:
1) "09/20/2021" can only be month/day/year (and not day/month/year as 
you specified).
2) The year is given with century, so it should be upper case Y

So
as.Date(ori[[n[3]]], format = "%m/%d/%Y")
should work.

HTH,
Ivan

--
Dr. Ivan Calandra
Imaging lab
RGZM - MONREPOS Archaeological Research Centre
Schloss Monrepos
56567 Neuwied, Germany
+49 (0) 2631 9772-243
https://www.researchgate.net/profile/Ivan_Calandra

On 14/12/2021 11:54, Luigi Marongiu wrote:> Hello,
> I have these kind of dates:
> ```
>> ori[[n[3]]]
> [1] "9/20/2021" "9/20/2021" "9/20/2021"
"9/20/2021" "9/20/2021" "9/20/2021"
> [7] "9/20/2021" "9/20/2021" "9/20/2021"
"9/20/2021" "9/21/2021" "9/21/2021"
> [13] "9/21/2021" "9/21/2021" "9/21/2021"
"9/21/2021" "9/21/2021" "9/21/2021"
> [19] "9/21/2021" "9/21/2021" "9/22/2021"
"9/22/2021" "9/22/2021" "9/22/2021"
> [25] "9/22/2021" "9/22/2021" "9/22/2021"
"9/22/2021" "9/22/2021" "9/22/2021"
> [31] "9/23/2021" "9/23/2021" "9/23/2021"
"9/23/2021" "9/23/2021" "9/23/2021"
> [37] "9/23/2021" "9/23/2021" "9/23/2021"
"9/23/2021" "9/24/2021" "9/24/2021"
> [43] "9/24/2021" "9/24/2021" "9/24/2021"
"9/24/2021" "9/24/2021" "9/24/2021"
> [49] "9/24/2021" "9/24/2021" "9/27/2021"
"9/27/2021" "9/27/2021" "9/27/2021"
> [55] "9/27/2021" "9/27/2021" "9/27/2021"
"9/27/2021" "9/27/2021" "9/27/2021"
> [61] "9/28/2021" "9/28/2021" "9/28/2021"
"9/28/2021" "9/28/2021" "9/28/2021"
> [67] "9/28/2021" "9/28/2021" "9/28/2021"
"9/28/2021" "9/29/2021" "9/29/2021"
> [73] "9/29/2021" "9/29/2021" "9/29/2021"
"9/29/2021" "9/29/2021" "9/29/2021"
> [79] "9/29/2021" "9/29/2021" "10/1/2021"
"10/1/2021"
> ```
> they look to me as month, date, year so I formatted them as:
> ```
>> as.Date(ori[[n[3]]], format = "%D")
> # or:  as.Date(ori[[n[3]]], format = "%d/%m/%y")
> [1] NA           NA           NA           NA           NA
> NA
> [7] NA           NA           NA           NA           NA
> NA
> [13] NA           NA           NA           NA           NA
> NA
> [19] NA           NA           NA           NA           NA
> NA
> [25] NA           NA           NA           NA           NA
> NA
> [31] NA           NA           NA           NA           NA
> NA
> [37] NA           NA           NA           NA           NA
> NA
> [43] NA           NA           NA           NA           NA
> NA
> [49] NA           NA           NA           NA           NA
> NA
> [55] NA           NA           NA           NA           NA
> NA
> [61] NA           NA           NA           NA           NA
> NA
> [67] NA           NA           NA           NA           NA
> NA
> [73] NA           NA           NA           NA           NA
> NA
> [79] NA           NA           "2010-01-20"
"2010-01-20"
> ```
> Why the conversion did not work?
> Thank you
>
> ______________________________________________
> R-help at r-project.org 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.
>

Micha Silver

2021-Dec-14 11:05 UTC

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[R] Format dates issues with R

On 14/12/2021 12:54, Luigi Marongiu wrote:> Hello,
> I have these kind of dates:
> ```
>> ori[[n[3]]]
> they look to me as month, date, year so I formatted them as:
> ```
Looks like that to me also.

>> as.Date(ori[[n[3]]], format = "%D")
> # or:  as.Date(ori[[n[3]]], format = "%d/%m/%y")

But you format as day, month, yr, not what you suggested.

Try: format = "%m/%d/%Y"


-- 

Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918

R help - Dec 2021 - Format dates issues with R

[R] Format dates issues with R

[R] Format dates issues with R

[R] Format dates issues with R

[R] Format dates issues with R