When doing yoga you can focus on your breath this helpful since yoga is also working with the breath

Important to remember. Also when you do difficult work like carrying heavy things, most people forget to breathe but that is when breathing is even more needed.

I've found it easier to count using breaths instead of seconds. One slow and deep inhale can reach up to 10 seconds and fels like time goes by faster while holding an asana for a period of time with much comfort as opposed to worrying about the seconds/minutes.