This post will summarize all the findings about managing time zones within Business Central (D365 BC).
As a Solution Admin, it is possible to manage all BC Environments accessing https://businesscentral.dynamics.com/[Tenant_ID]/admin.
Under the same tenant, it is possible to have several Environments (Databases). A license includes 1 Production environment and 3 Sandboxes environments.
If required, it is possible to have additional environments adding extra Dynamics 365 Business Central Additional Environment Addon.
Each Environment (Database) can be defined with Country/Region and Azure Region.
The Country/Region will define the localisation.
The Azure Region will define the Azure region where the data is stored.
There is no information about the Time Zone!
As a End User and under My Settings, there is the Time Zone field. This field allow to select the Time Zone to be used by each user. This way, a user can be one day accessing to a UK Environment/Company with UTC time zone but on other day, accessing to the same UK Environment/Company with Central Standard Time (UTC-06:00).
So this field is by user and can be define by session (with each login).
As a Database Manager, when we access directly to the database/records, there are some columns with date/time format. All these columns have the time/zone based in UTC as the environment is time zone agnostic.
Practical example for an environment:
Country/Region - JP
Azure Region - Southeast Asia
TimeZone - UTC
End User 1: Can have Time Zone UTC +00:00 under My Settings
End User 2: Can have Time Zone UTC -06:00 under My Settings
When the End User 2 is using this environment with Time Zone UTC -06:00, if he populates a date/time, BC will convert automatically between UTC -6:00 to UTC +00:00 to store the information in the database as UTC +00:00.
This logic should be applied to the custom interfaces importing/exporting date/time information to/from BC. All the date/time columns are stored as UTC +00:00 so if a Time Zone conversion is required, it should be handled by the custom/interface. Same for external reporting tools.