I am trying to do the following within a query but am getting a bit stuck, can you help me please?

I want to round these 2 datapoints below to the nearest 15 minute interval from Leads (ZOHO CRM) and Deals (ZOHO CRM)

Leads.”Created Time”

Deals.”Created Time”

Deals.”First Activity Time”

But I want to group those based on the stage of the deal as well