Fixing Schedule-Based Date Calculation Issue in ServiceNow

Praveena Patel · 2 hours ago

Overview

In recent times, I came across a requirement to automatically populate a date field (custom field – RCA due date) on Problem records during creation.

This article explains the issue encountered initially and the improved solution.

Requirement:

Auto-populate a date field on Problem record creation, calculate based on a defined business schedule (e.g., 8 AM to 5 PM), and add 5 working days (excluding non-working time).

Initial Approach:

An After Business Rule was created with the following logic:

Loop through each day
Check if the day falls within the schedule
Continue until the required number of working days is reached

(function executeRule(current, previous /*null when async*/ ) {

    if (current.due_date.nil()) {
        var schedule = new GlideSchedule();
        schedule.load('090eecae0a0a0b260077e1dfa71da828');

        var gdt = new GlideDateTime();
        var workingDaysToAdd = 5;
        var workingDaysAdded = 0;

        while (workingDaysAdded < workingDaysToAdd) {
            gdt.addDaysLocalTime(1);

            if (schedule.isInSchedule(gdt)) {
                workingDaysAdded++;
            }
        }

        current.due_date = gdt;
        current.update();
    }

})(current, previous);

Issues Observed When record created after Schedule Hours:

Problem records were delayed during creation
Problem module hanging
Some transactions took longer or failed

Why This Caused Issues:

When a record was created outside the defined schedule hours, the condition to increment workingDaysAdded was not met. As a result, the loop continued indefinitely, leading to an infinite loop, which caused delays and performance issues.

Optimized Solution:

The solution was redesigned to remove loops and use a more efficient approach.

Key Improvements

Convert working days into total working hours
Use GlideSchedule.add() for direct calculation
Avoid loops and recursive updates

Updated Script

(function executeRule(current, previous /*null when insert*/) {

   
    var startTime;
    if (current.sys_created_on) {
       
        startTime = new GlideDateTime(current.sys_created_on);
    } else {
       
        startTime = new GlideDateTime();
    }
   
    var hours = 45;
    var dur = new GlideDuration(60 * 60 * 1000 * hours);
    var schedule = new GlideSchedule('090eecae0a0a0b260077e1dfa71da828'); 
    var end = schedule.add(startTime, dur);
	current.due_date = end;
	//current.update();
	
})(current, previous);

The above Business rule is more efficient with no impact on record creation performance, Cleaner and more maintainable code

I hope this article helps when working on similar schedule-based date calculation scenarios in ServiceNow.

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