DateTime field values displayed on the UI with regards to Daylight Saving Time and Viewing User's Locale

Salesforce follows industry standards to convert UTC to Local Time (based on Viewing User's Locale) when rendering and displaying a DateTime field in UI. The value of the field displayed on the UI depends on the "Actual Value" present in this field, and the viewing User's Locale.

This value does not depend on the Day/Date on which the field was modified and will remain the same irrespective of at which time (Within DST or Outside DST) the record is being viewed.

Let's consider an example of a User having User Locale Set To: (GMT+00:00) Greenwich Mean Time (Europe/London), for which Day Time Saving is applicable:

United Kingdom Day Time Saving period in 2023, Sunday of March (March 26, 2023) at 01:00 am, and will go back by an hour at 02:00 am on the last Sunday in October (October 29, 2023)

If viewing the DateTime field value in Salesforce on any record:

Assuming that an object has the following two DateTime Fields
DateTime1__c
DateTime2__c

Scenario 1: Login as a User with Locale (GMT+00:00) Greenwich Mean Time (Europe/London) and enter the following values in the UI
DateTime1__c =18th Aug 2023, 14:00 /* this Day/DateTime is within the UK 2023 DST period
DateTime2__c =1st Dec 2023, 14:00 /* this Day/DateTime is outside DST period

The following data will be stored in the database:

DateTime1__c =18th Aug 2023,  13:00 GMT+00:00:00
DateTime2__c =1st  Dec 2023,  14:00 GMT+00:00:00

Scenario 2: Login as a User with Locale (GMT+00:00) Greenwich Mean Time (Europe/London) and display the above records

The following data will be displayed on the UI

DateTime1__c =18th Aug 2023, 14:00.
DateTime2__c =1st Dec 2023, 14:00.

Scenario 3: Login as User with (GMT+00:00) Greenwich Mean Time (GMT) to display the above records

The following data will be displayed on the UI

DateTime1__c =18th Aug 2023, 13:00.
DateTime2__c =1st  Dec 2023, 14:00.

If any end user wants to check whether a DateTime field value being shown on the UI is influenced by DST, they only need to check the "Actual Value" presented in the DateTime field and the Timezone of the Login User. The DateTime on which the field value was modified has neither an impact on the value displayed on the UI nor an impact on the value stored in the database.