Symptoms

While using date picker with the date / date time fields on service portal, getting below javascript error,

moment-timezone-with-data.js:476 zone.offset has been deprecated in favor of zone.utcOffset

Complete error stack is shown in below screenshot,

Release

Any supported release. 

Cause

Older version of moment.js third party library (/ajax/libs/moment.js/2.22.2/moment.min.js) was included in the out of the box provided "moment.js" widget dependency (https://InstanceName.service-now.com/nav_to.do?uri=sp_dependency.do?sys_id=db6689c1cb11120000f8d856634c9c3b).

Hence system loads the older version of moment.js in DOM and eventually we get the error "zone.offset has been deprecated in favor of zone.utcOffset" while accessing date /date time field since older version of moment.js library has deprecated methods.

Resolution

Out of the box provided moment.js widget dependency has following definition,

Name = moment
Application = Global
Included on Page load = false

JS Includes,
order = 200, JS Include = /scripts/thirdparty/moment-timezone-0.4.0/moment-timezone-utils.js, JS file URL = /scripts/thirdparty/moment-timezone-0.4.0/moment-timezone-utils.js

order = 200, JS Include = /scripts/thirdparty/moment-jdateformatparser-1.0.2/moment-jdateformatparser.js, JS file URL = /scripts/thirdparty/moment-jdateformatparser-1.0.2/moment-jdateformatparser.js

Hence, we recommend, updating your "moment.js" widget dependency as per the out of the box definition 

OR

Keep the out of the box provided version and delete the custom moment.js widget dependency.

Additional Information

Create a Widget dependency

Moment.js community thread