Get-Date -UFormat %x does not match reference implementation

[brianary]

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues.
• Refer to the FAQ.
• Refer to Differences between Windows PowerShell 5.1 and PowerShell.

Steps to reproduce

Get-Date -UFormat %x

Currently, "{0:MM/dd/yy}" is being used, but "{0:MM\/dd\/yy}" is a better match (though "{0:d}" is a reasonable match for the definition). See Date conversion specifiers or strftime.

Expected behavior

Based on running the `date -d $date +%x` as a reference implementation (see Environment for details).

PS> Get-Date 1999-01-01 -UFormat %x
01/01/99
PS> Get-Date 2000-02-14 -UFormat %x
02/14/00
PS> Get-Date 2001-03-29 -UFormat %x
03/29/01
PS> Get-Date 2002-05-12 -UFormat %x
05/12/02
PS> Get-Date 2003-06-25 -UFormat %x
06/25/03
PS> Get-Date 2004-08-07 -UFormat %x
08/07/04
PS> Get-Date 2005-09-20 -UFormat %x
09/20/05
PS> Get-Date 2006-11-03 -UFormat %x
11/03/06
PS> Get-Date 2007-12-17 -UFormat %x
12/17/07
PS> Get-Date 2009-01-29 -UFormat %x
01/29/09
PS> Get-Date 2010-03-14 -UFormat %x
03/14/10
PS> Get-Date 2011-04-27 -UFormat %x
04/27/11
PS> Get-Date 2012-06-09 -UFormat %x
06/09/12
PS> Get-Date 2013-07-23 -UFormat %x
07/23/13
PS> Get-Date 2014-09-05 -UFormat %x
09/05/14
PS> Get-Date 2015-10-19 -UFormat %x
10/19/15
PS> Get-Date 2016-12-01 -UFormat %x
12/01/16
PS> Get-Date 2018-01-14 -UFormat %x
01/14/18
PS> Get-Date 2019-02-27 -UFormat %x
02/27/19
PS> Get-Date 2020-04-11 -UFormat %x
04/11/20

Actual behavior

PS> Get-Date 1999-01-01 -UFormat %x
01-01-99
PS> Get-Date 2000-02-14 -UFormat %x
02-14-00
PS> Get-Date 2001-03-29 -UFormat %x
03-29-01
PS> Get-Date 2002-05-12 -UFormat %x
05-12-02
PS> Get-Date 2003-06-25 -UFormat %x
06-25-03
PS> Get-Date 2004-08-07 -UFormat %x
08-07-04
PS> Get-Date 2005-09-20 -UFormat %x
09-20-05
PS> Get-Date 2006-11-03 -UFormat %x
11-03-06
PS> Get-Date 2007-12-17 -UFormat %x
12-17-07
PS> Get-Date 2009-01-29 -UFormat %x
01-29-09
PS> Get-Date 2010-03-14 -UFormat %x
03-14-10
PS> Get-Date 2011-04-27 -UFormat %x
04-27-11
PS> Get-Date 2012-06-09 -UFormat %x
06-09-12
PS> Get-Date 2013-07-23 -UFormat %x
07-23-13
PS> Get-Date 2014-09-05 -UFormat %x
09-05-14
PS> Get-Date 2015-10-19 -UFormat %x
10-19-15
PS> Get-Date 2016-12-01 -UFormat %x
12-01-16
PS> Get-Date 2018-01-14 -UFormat %x
01-14-18
PS> Get-Date 2019-02-27 -UFormat %x
02-27-19
PS> Get-Date 2020-04-11 -UFormat %x
04-11-20

Error details

No response

Environment data

Name                           Value
----                           -----
PSVersion                      7.4.0
PSEdition                      Core
GitCommitId                    7.4.0
OS                             Microsoft Windows 10.0.22621
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

WSL Ubuntu details:

$ uname -a
Linux localhost 5.15.133.1-microsoft-standard-WSL2 #1 SMP Thu Oct 5 21:02:42 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

Visuals

No response

[237dmitry]

date -d $date +%x as a reference implementation

%x 	Date in standard format for locale 	06/27/19 for English-US

Get-Date

From man date:

%x     locale's date representation (e.g., 12/31/99)

But it returns:

[brianary]

@237dmitry
Since it's locale-dependent, it could be due to your OS settings.