A common feature in other platforms I have used such as Homeseer is the option to quickly and easily create a timer within the Graphical Editor that can be used to track the “on” time of a device or for other situations where you need to track accumulated time.
I will typically use these to track things like the total run time of my furnace during the day etc. Because they are defined and used in the Graphical Editor it is very easy to quickly create a new duration timer and then use simple logic in an automation to manage it. I can RESUME a timer when an entity like my furnace goes on and PAUSE the timer when it goes off. The timer will count up from zero in one second increments unless preloaded with a different starting point.I can have a TTS message tell me the run time so far at any point in the day and I can RESET the timer with another automation that runs at midnight. The entire process of defining a timer and setting up the automations to track daily on time of a device takes less than 5 minutes in Homeseer and is done entirely within the Graphical Editor.
I have seen many posts where folks have tried to do something similiar in Home Assistant but it always becomes needlessly complicated for such a simple feature.
A simple Helper timer designed to count up from zero for use in tracking accumulated time for something without resorting to YAML would be a much more useful way to accomplish this.