Replace existing timer with the custom one.

Replace the existing timer with the custom one. It is coded already here:
https://www.w3schools.com/code/tryit.asp?filename=FFC2S77145QP

It needs to be replaced with the existing time on this (and all products):
https://www.yourgadget.co.uk/product/apple-watch-leather-loop-band-strap-series-1-2/

Just static JavaScript insertion is fine.

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