DateTimePicker with custom format auto increments when focus is changed

[xceedsoftware]

diiode[CodePlex]
This bug is found in the community edition of Extended WPF Toolkit atleast since version 2.0. The bug itself is in the
DateTimePicker-control.

Description
When the format of an DateTimePicker is custom set to the FormatString=quotyyyy-MM-ddTHH:mm:ssZquot and the user changes focus between
DateTimePicker-controls, the previous focused control auto increments it's hour with 2.

How to reproduce

Run the code underneath Fill in the two DateTimePicker-controls with a (random) date Tab between/or change focues between the two controls
-gt The datetime will be auto-incremented.

Code:
ltWindow x:Class=quotWpfApplicationDateTimePickerTest.MainWindowquot
xmlns=quothttp://schemas.microsoft.com/winfx/2006/xaml/presentationquot
xmlns:xctk=quothttp://schemas.xceed.com/wpf/xaml/toolkitquot
xmlns:x=quothttp://schemas.microsoft.com/winfx/2006/xamlquot
Title=quotMainWindowquot Height=quot350quot Width=quot525quotgt
ltGridgt
ltGrid.RowDefinitionsgt
ltRowDefinition Height=quotAutoquot /gt
ltRowDefinition Height=quotAutoquot /gt
lt/Grid.RowDefinitionsgt
ltGrid.ColumnDefinitionsgt
ltColumnDefinition Width=quotAutoquot /gt
ltColumnDefinition Width=quotAutoquot /gt
lt/Grid.ColumnDefinitionsgt

    ltLabel Grid.Row=quot0quot Grid.Column=quot0quotgt
        Timepicker 1
    lt/Labelgt
    ltxctk:DateTimePicker Grid.Row=quot0quot Grid.Column=quot1quot x:Name=quotDtck1quot Width=quot200quot
                         Format=quotCustomquot FormatString=quotyyyy-MM-ddTHH:mm:ssZquot TextAlignment=quotLeftquotgt
    lt/xctk:DateTimePickergt
    ltLabel Grid.Row=quot1quot Grid.Column=quot0quotgt
        Timepicker 2
    lt/Labelgt
    ltxctk:DateTimePicker Grid.Row=quot1quot Grid.Column=quot1quot x:Name=quotDtck2quot
                         Format=quotCustomquot FormatString=quotyyyy-MM-ddTHH:mm:ssZquot TextAlignment=quotLeftquotgt

    lt/xctk:DateTimePickergt
lt/Gridgt

lt/Windowgt

[xceedsoftware]

BoucherS[CodePlex]
Will be fixed in v2.4.
A new Property Kind will be added on a DateTimeUpDown.
Z won't be necessary when editing a DateTime.

[xceedsoftware]

diiode[CodePlex]
Thanks,

Using standard format u is a working solution for my use case.

[xceedsoftware]

emartin[CodePlex]
I found the issue.
The handling of Z in .net seems to be a bit special:

http://stackoverflow.com/questions/833102/wheres-the-datetime-z-format-specifier

What cause the increment, is that when the text is parsed, it is interpreted has Zulu (Utc) time, (which it is your intention anyway), but when it come to convert the datetime to string, the ToString call just write the local time and add the Z
at the end just like it would with some random character.

To avoid such problems, I would suggest to use the standard u format that is quite similar to yours. (except for the T).
xctk:DateTimePicker Format=Custom FormatString=u/

Has about how to fix that..... I just don't want to get into checking the format string and handle all the possible issues (like the Z). Microsoft did the job in DateTime.Parse, re-inventing the wheel would be an endless source of bugs...
The eventual solution would be to add some Kind property to the DateTimePicker to specified the intended date kind.