Django: Logging to custom files every day - django

Question

I'm running Django 3.1 on Docker and I want to log to different files everyday. I have a couple of crons running and also celery tasks. I don't want to log to one file because a lot of processes will be writing and debugging/reading the file will be difficult.
If I have cron tasks my_cron_1, my_cron_2,my_cron_3
I want to be able to log to a file and append the date
MyCron1_2020-12-14.log
MyCron2_2020-12-14.log
MyCron3_2020-12-14.log
MyCron1_2020-12-15.log
MyCron2_2020-12-15.log
MyCron3_2020-12-15.log
MyCron1_2020-12-16.log
MyCron2_2020-12-16.log
MyCron3_2020-12-16.log
Basically, I want to be able to pass in a name to a function that will write to a log file.
Right now I have a class MyLogger
import logging
class MyLogger:
def __init__(self,filename):
# Gets or creates a logger
self._filename = filename
def log(self,message):
message = str(message)
print(message)
logger = logging.getLogger(__name__)
# set log level
logger.setLevel(logging.DEBUG)
# define file handler and set formatter
file_handler = logging.FileHandler('logs/'+self._filename+'.log')
#formatter = logging.Formatter('%(asctime)s : %(levelname)s: %(message)s')
formatter = logging.Formatter('%(asctime)s : %(message)s')
file_handler.setFormatter(formatter)
# add file handler to logger
logger.addHandler(file_handler)
# Logs
logger.info(message)
I call the class like this
logger = MyLogger("FirstLogFile_2020-12-14")
logger.log("ONE")
logger1 = MyLogger("SecondLogFile_2020-12-14")
logger1.log("TWO")
FirstLogFile_2020-12-14 will have ONE TWO but it should only have ONE
SecondLogFile_2020-12-14 will have TWO
Why is this? Why are the logs being written to the incorrect file? What's wrong with my code?