Show system notification event time wise

like event time is 10:00AM so system notification send 9:45 AM.Simple show notification 10-15 minutes before start event

Use Cronjob

you have any idea how perform cron job?

Yes you will use python coding schedule event from 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.

any update?