Potions timer

So to my understanding: Boosted levels from potions degrade by 1 every time the "global runescape timer" of 60 seconds refreshes.

am I able to somehow see and keep track of this timer? Is it just identical to the real world clock?

I am already aware of the third party clients that allow you to see exactly when you should re pot, are there any other ways?

I ask this because I wish to maintain my max hit potential while pking

Thanks