def get_start_time():
 start_time = (datetime.datetime.utcnow() - datetime.timedelta(hours=1, minutes=5))
 return format_rfc3339(start_time)

def get_start_time ( ) : start_time = ( datetime . datetime . utcnow ( ) - datetime . timedelta ( hours = 1 , minutes = 5 ) ) return format_rfc3339 ( start_time )
returns the start time for the 5-minute window to read the custom metric from within .