I have one table called 'Issues' has a field called 'due_date' having field type 'date' and another

[Abhishek Kathe]

I have one table called 'Issues' has a field called 'due_date' having field type 'date' and another field called 'assigned_to' having 'reference' field type referes to 'sys_user' table, so I want to send an email to a person who is present in 'assigned_to' field one day before the 'due date'. 

[Dr Atul G- LNG]

Hi @Abhishek Kathe 

You can use the flow designer for this.

The good link 

https://www.servicenow.com/community/developer-forum/flow-designer-reminder-emails/m-p/2413189

https://www.servicenow.com/community/developer-forum/how-to-send-an-email-notiffication-to-assigned-...

https://www.servicenow.com/community/developer-forum/is-it-possible-to-create-a-notification-7-days-...

[Anil Lande]

You can use scheduled job and event based notifications.

In your script make a query to 'Issue' table and filter records where Due date is tomorrow.

For all records trigger event based notification.

[Anil Lande · Accepted solution]

Your scheduled job script would be like below:

var issueGr = new GlideRecord('u_issue');  // replace yourbtable name
issueGr.addEncodedQuery('due_dateONTomorrow@javascript:gs.beginningOfTomorrow()@javascript:gs.endOfTomorrow()');  // replace your due date field name
issueGr.query();
while(issueGr.next()){
gs.eventQueue('reminder.event_name',issueGr,'');  // add event name as per your configuration.
}

Check below links to learn more about event based notification.

https://www.youtube.com/watch?v=YSZFiumGXj4

https://www.youtube.com/watch?v=K4J9oay7Zwk