@Joao Pedro Alves It's difficult to say for sure without more information, but it's possible that the time zone settings on your Azure Cognitive Search resource or the machine making the API call are not set correctly.
When you create an indexer in Azure Cognitive Search, you can specify a start time for the indexer to run. This start time is based on the time zone of the resource. If the time zone is not set correctly, the indexer may run at a different time than expected.
You can check the time zone setting for your Azure Cognitive Search resource by going to the Azure portal, selecting your search resource, and then selecting "Settings" > "Time zone". Make sure the time zone is set correctly for your location.
If the time zone setting is correct, you may want to check the time zone settings on the machine making the API call. If the time zone is not set correctly on the machine, it could be causing the API call to be made with the wrong timestamp.