like event time is 10:00AM so system notification send 9:45 AM.Simple show notification 10-15 minutes before start event
you have any idea how perform cron job?
Yes you will use python coding schedule event from hooks.py file
@mahemudhusain_amafhh cron job same event repeat every same time like every 10 minutes,every 1 hour.
But in that case you set a reminder on the next contact date of the lead such that the notification should be shown 10-15 minutes before the next contact date.