Do you have an official document confirming the setting of the spot date for individual currency pairs?
If you're looking for official documents on methodologies used in Refinitiv services, the best self-help resource is MyRefinitiv. If you cannot find what you're looking for on MyRefinitiv, then I would suggest contacting Refinitiv Helpdesk (which you can do by following Get Support prompts on MyRefinitiv).
Is there a context to your question? Does it pertain to a specific product or service? Refinitiv products should be following the market convention in determining the spot date for a currency pair.
This forum is dedicated to software developers using Refinitiv APIs. For any other enquiries, please contact Refinitiv Helpdesk. If your question is related to a Refinitiv API, would you mind specifying which API you're using? If it's not related to Refinitiv APIs, then please contact the Helpdesk.