I've tried to make a timer in Javascript using the built-in Date() method, but this dosn't show the special 23:59:60 that I want [1] (only true at timezone +0000). As a side question, how is the leap second handled in JS? I also tried python's Datetime object, but that has the same results as in JS.

Is there a website or library to use that will show be a simple accurate date and time with a count down that goes to 60?

[0] https://www.nasa.gov/feature/goddard/2016/space-timekeeping-nasas-sdo-adds-leap-second-to-master-clock [1] http://imgur.com/a/4L2bh