Timer activation whit GPIO

Hi folks,

I'm new to the Node world and I've a little project on the table for quite some time, and I couldn't end it.

Basically I need to make a visual interface for 3 timer who will increment seconds, and display HH:MM:SS time, based on GPIO input activation.

Each input control a separate timer that could be manually and individually reset by a button, or all at once, in the web interface.

I've made a couple attempts in the past without any real success.
The major problem for me is to make the timer increment when the GPIO is HIGH. The data transformation and display part is more easy to understand but a little help could be appreciated.

So, without making the code, can someone is able to help me out with this "problem" !?!