Calcualting duration between two date fields in scoped application

[Chad7]

I'm used to calculating duration fields using dateDiff, but since that doesn't work in my scoped application, I'm having to use GlideDateTime.subtract, which I can't get to work on my business rule that is triggered when the start date or stop date changes. Can anyone tell me why this script isn't working as written? I get no errors, but the degradation_duration field just remains blank.

var start = new GlideDateTime(current.degradation_start.getDisplayValue());
var stop = new GlideDateTime(current.degradation_stop.getDisplayValue());
var duration = GlideDateTime.subtract(start, stop).getDisplayValue();

current.degradation_duration = duration.getDisplayValue();

[Ankur Bawiskar]

Hi Chad,

Following links should be helpful:

https://community.servicenow.com/community?id=community_question&sys_id=11010fa5db98dbc01dcaf3231f96194f

Following example:

var date1 = new GlideDateTime(current.degradation_start + ' 00:00:00');

var date2 = new GlideDateTime(current.degradation_stop + ' 00:00:00');

var dateDiff = GlideDateTime.subtract(date1,date2);
var durationStr = dateDiff.getDurationValue();

Mark Correct if this solves your issue and also hit Like and Helpful if you find my response worthy based on the impact.
Thanks
Ankur

[Chad7]

Even using your example, the field remains blank.

[Abhinay Erra]

What are the field types of degradation_start, degradation_stop, degradation_duration

[Chad7]

Respectively-- Date/Time, Date/Time, Duration