Countdown timers

[Wayne Irvine]

I am looking to create a system to administer and report on a series of timed services. I have most of it in place. I can create a new record for one hour, or 2 hours or whatever and produce reports daily weekly or monthly.

The bit I am missing out on is a countdown timer for each event (portal record). When I create a new record with a value of 60 minutes I would like to include a timer which you can start, pause, stop, add X minutes to etc. When this timer expires I would like to sound a chime until acknowledged.

There would be more than one record visible in the portal simultaneously and all could have active timers running.

Is this possible? Are there countdown timer plugins or functions I should investigate?

[comment]

I have done something similar using Javascript in web viewer - see: 
https://fmforums.com/topic/71934-calculating-elapsed-time-realtime/?do=findComment&comment=340205