Understanding the stopwatch i found

[CHHE-ledtec]

hi iam using the template from this to use in my system

Countdown timer

Hi. This is my first post and don't know mouth about java scrips and need some( a lot) of help. Im urgently looking for a count down timer as the one we been using stopped working its about 10 yours old, so looking to upgrade it to something better and node red ui is perfect for what i want to do. (every one on the network can see it) [Screenshot_20210621-123035_Samsung Internet (2)] Is there anyone that can help me under stand this concept to make it work. Countdown clock.json (5.4 KB)

i am trying to figure out to count up instead of down ..

but what i really want is be able to use a slider to switch between count up or count down.

anyone who can point me in the right direction.

i am not that good in javascript i dont really follow how it is counting down right now.