The #DmZ# tag checks for the current minute.. so 00 is the first minute, 30 is the halfway point.
As far as the sin stuff goes, think of it this way..
The middle horiztonal line/axis is 0.. think of it as the timeline for your watch. You could try and specify a time to trigger an animation but not everyone is going to have their watch on at the same time.
TRANSLATION: I look at my watch at 9:15:15 but you might look at your watch at 3:21:35. If you tell the animation to animate from 0 to 30 seconds, you won't see the animation at all, until your watch's time is 3:22:00 which is 25 seconds away. And even then, some watches won't stay awake that long, so a lot of people will miss out on the animation.
That's why people use the #DWE# tag which triggers every time you look at your watch ("wakes up").. so you checking at 3:21:35 and me checking 9:15:15 starts the animation at the same point if that makes sense.
Ok, now back to the timeline. Let's say the graph shows how the animation looks while it's animated. Since this is in the Transparency field it changes the transparency based on the values shown. For simplicity sake (not accuracy) let's say the top and bottom are 100. At 0 seconds, it's at 0 transparency.. let's say the top is 3 seconds.. so at 3 seconds the value is set to 100 transparency. Now the graph takes a downturn back to 0... again, paraphrasing, let's say at 6 seconds, it reaches back to 0 (the middle line). The top arc just made your graphic cycle from 0 (off) to 100 (on) and back to 0 (off) over the course of 6 seconds. When it goes through the bottom arc, it's repeating the same on/off cycle.
The reason why people use sin/cos waves is they're consistent and we can use that predictabilty. Putting it in transparency can cycle on and off.. in X and Y fields you can move an object back and forth between two points. In the height/radius fields it can make an object grow/shrink. All the extra stuff modifies the curve making the aforementioned actions faster/slower/bigger/smaller/etc.
Luckily you don't need to know much math as a lot of these "formulas" are on the board. The best advice I would give is to look up ones and try them. See what they do, and how tweaking a number affects things. Many times these formulas are explained a lot better than I'm doing
LONG STORY SHORT (too late!)
The reason it always stayed off when you tried it, is because in the facer editor you have to simulate the "waking" function to trigger #DWE#.. You can do so by clicking the play button (this simulates the watch being on) then clicking on the DIM tab, followed by the ACTIVE tab. You'll need to be careful not to hover over any of your layers as that will stop the "play" simulation as Facer thinks you're trying to edit a layer.
Another roundabout way you can accomplish the same thing (without triggering edit mode) is to click on Showcase mode. On the right side of the edit pane you'll see three buttons. A disk, a watch, and a blue watch. The one you'll want is the middle one. Hovering over it you'll see it labeled Showcase mode. This will open the design and simulate what it'd look and perform like. From here you can toggle dim/active mode by pressing the Sun icon (2nd icon on the left)
I know it's a lot to throw at you but the formula will work, you just have to simulate the act of waking the watch up using either of these two methods.
Another complication.. you want to see it trigger at 0 and 30 minutes.. you're only going to see the results at these times.. so you have to speed up time until it reaches 0 or 30. One click on the play button should speed it up.. if you click it more than once it'll go too fast. So you'll have to be patient or test it near the top/bottom of the hour.
Anyways, here's what it looks like when the below is added to the transparency field:
(Keeping in mind, this simulation is running at increased speed, the glow effect looks better when running at normal speed.. it's also proof it works on the hour)
(Here's what it looks like at normal speed)
Again, I know it's a lot of information but I can clarify and simplify (I hope!) if you want
If it's too bright we can tweak the formula so it goes from 0 to 50 or whichever value looks better.