In a python recipe you can use this code to set the project variable at the name of current month. You'll have to rerun it every month with a scenario.
import dataiku from datetime import datetime
projectKey = dataiku.get_custom_variables()["projectKey"] c = dataiku.api_client() p = c.get_project(projectKey) v = p.get_variables() v["standard"]["current_month"] = datetime.now().strftime('%B') p.set_variables(v)