This is true but you could allow the user to set an offset.
This is exactly the hidden complexity that HN users love to add to products that adds no real value and sells no extra product
Anyways, android and iOS and Mac and windows and etc all have the ability to fetch time or use gps to set time with a user override to do their own tricks. We all woke up today so I think the world survived.
Does anyone here with an Apple Watch use the time offset feature?