Ivan is writing an api query, and from the api’s documentation he finds out that the response can be filtered to only show data created since a defined date (using the “created_since” parameter). Ivan wants to filter the data that was created since the beginning of the month, and the input format of the “create_since” parameter should be “yy MMM dd”. What is the date/time function Ivan should pass to the “created_since” paramter in his query?