new Date().get('timezone'); Always returns GMT

[jbgithub]

The value/format returned by Date.toString() has changed. I checked this in Chrome, Firefox, Internet Explore and Edge.

I'm located in the America/Los_Angeles timezone, here is an example of what is returned:

Wed Nov 22 2017 16:47:56 GMT-0800 (Pacific Standard Time)

The regular expression use in getTimezone() always returns GMT:
this.toString() .replace(/^.? ([A-Z]{3}).[0-9]{4}.$/, '$1')
.replace(/^.*?(([A-Z])[a-z]+ ([A-Z])[a-z]+ ([A-Z])[a-z]+)$/, '$1$2$3');

I modified the first RE to remedy the issue:
this.toString() .replace(/^.* (([A-Za-z ]+)|[A-Z]{3}).$/, '$1')
.replace(/^.?(([A-Z])[a-z]+ ([A-Z])[a-z]+ ([A-Z])[a-z]+)$/, '$1$2$3');

With this modification, PST is now returned. This works for the 4 US time zones. You will probably need additional changes for other time zones.