Run Django Celery Periodically

Question

I have the task file tasks.py

@shared_task
def add(x, y):
    print(x + y)
    return x + y

and celery.py

from __future__ import absolute_import, unicode_literals
import os
from celery import Celery
from celery.schedules import crontab

# setting the Django settings module.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'onboarding.settings')
app = Celery('onboarding',broker='pyamqp://guest@localhost//')
app.config_from_object('django.conf:settings', namespace='CELERY')

# Looks up for task modules in Django applications and loads them
app.autodiscover_tasks()
app.conf.beat_schedule = {
    # Executes every Monday morning at 7:30 a.m.
    'add-every-1-seconds': {
        'task': 'tasks.add',
        'schedule': 30,
        'args': (16, 16),
    },
}

when i run celery -A onboarding beat

and celery -A onboarding worker

Seems it is adding tasks but it is not executing the tasks required. What can be the problem