Java 8 : Using Instant, How to retrieve ZoneId information

Question

I'm using Java Instant for my use-case where I want to capture the exact moment in timeline for.eg, { When the user last visited my website }. This is when the data gets persisted in the backend (sql). It persists in UTC format as I use Instant.now();

As my website is used across all Zones (In the world), When the user lands on the homepage, I want to show the dateTime (when he last visited the website) as localDateTime as per his zoneId.

How do I get the ZoneId Information?

As my website is currently hosted in 2 servers and both servers are in India, If I do ZoneId.systemDefault() , I always get Indian ZoneId (Asia/Kolkota). So, the conversion is not possible.

If Someone from US hit's my server, How do I get the zoneId as US in my server?

Answer 1

The best would be to keep things simple.

Just use UTC to store visit time. Frontend can convert UTC into browser's (thus user's) timezone.