Multiple Timers, Multiple Events

I am well experienced in Excel, but am starting my first real VBA project. I have typically found what I've needed in the past and copied and pasted it, but I know that won't be the case for this project. I have researched event handlers and basic countdown timers, but I haven't figured out how to piece this idea together.

Basically, I need a separate hour long timer in each row that starts when something is entered into that row's column B. With just a basic timer and event handler, I'm able to call a start_timer when something is entered into B:B, but that only works with one row. I have thought of running separate modules per row (start_timerF, start_timerG, etc.) but that would be dozens of modules running and I doubt that's the best way to move forward. I'm not necessarily hoping for a copy paste answer, though that would be incredible. I'm just hoping someone here knows of the right path forward for me to figure this out. I appreciate your time and any help you can provide!