Sitefinity Classic Editor DateTime format

Issues
1/ Content Edit Page – Show mm/dd/yyyy

2/ Content Listing Page – Show unknown (AM / PM) time

What I did to resolve it?

1/ Add a new ViewMap Control

Advanced Settings → Controls → ViewMap → <Create new>
HostType: Telerik.Sitefinity.Web.UI.Fields.DateField, Telerik.Sitefinity
Layout: ~/Utils/Extensions/DateFieldExtended.ascx

Sample: DateFieldExtended.ascx (github.com)

2/ Update Content Type Listing DateTime Format

Advanced Setting → DynamicModules → Controls → <Custom Module Backend Definition> → Views → <Module Backend List> → View Modes → Grid → Columns → <Field> → Client Template →
<span>{{ (Start) ? Start.sitefinityLocaleFormat(‘dd/MM/yyyy hh:mm tt’): ‘-‘ }}</span>

Do for LastModified, DateCreated fields too.

Resolved Screen

Content Edit Screen

Content Listing Screen

References:

1. https://community.progress.com/s/article/How-to-change-the-time-format-of-the-date-field-when-creating-Events-in-Sitefinity
2. https://community.progress.com/s/article/after-upgrade-datepickers-are-not-working