celerybeat set to crontab(day_of_month=1) sends task multiple times in a month

celerybeat set to crontab(day_of_month=1) sends task multiple times in a
month

I have this task which is set to crontab(day_of_month=1). But then when it
perform the tasks in continues to send task minutely which is supposed to
perform once.
from my tasks.py
from celery.task.schedules import crontab
@periodic_task(run_every=crontab(day_of_month=1))
def Sample():
...
Am I missing something?