These reflect the trigger device name (%device%), the event value (%value%), and the date of that event (%date%), the latter two meaning the event on the trigger device. You might get that last one or maybe the last two for a "certain time" trigger, but I would not count on any of them because you don't have a device as a trigger. Conditionals in your actions do not affect the values of these, which it sounds like you might be expecting. See: Rule 5.1 | Hubitat Documentation
Are you trying to get a notification every day at a certain time? If so, you'd need to either build a string with a conditional for each device (less awkward to receive but may be harder to make) or use a separate conditional and notification for each device (probably gets more potentially awkward the more devices you have but might be OK for just a few). You could also look into a custom app, such as this one I wrote: [RELEASE] Device Activity Check - Get notifications for "inactive" devices (you can do exactly what you want if you use "Battery" as the detection type, but you might actually want to use "Last activity at" if that is what you really care about, as battery can be unreliable...but you can find lots of discussion on that here).