Get user’s current default time zone within a Vaadin 8 app

Question

Is there a way to determine the user’s web browser’s current default time zone from within a Vaadin 8.1 app?

Preferably get a ZoneId object rather than the legacy class TimeZone.

The WebBrowser class offers getter methods for getCurrentDate(), getDSTSavings(), getRawTimezoneOffset(), getTimezoneOffset(), and isDSTInEffect(). But none of those are a ZoneId. A mere offset is not a time zone. A time zone is a history of offset-from-UTC for a particular region, covering past, present, and future changes such as Daylight Saving Time (DST).

I am aware that ultimately the only reliable way to know the user’s desired/expected time zone is to explicitly ask them in my app. But it would be nice to have a guess as a default.

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The proposed duplicate is not a duplicate, asking about getting the current date-time whereas my Question is about the time zone. Furthermore, my Question asks about the modern java.time classes while the proposed Question is about the flawed legacy date-time classes.

Answer 1

An alternative for querying WebBrowser (or any other Vaadin API) is to use the client IP address and use a online service to get the geo information, including ZoneId.

See related Questions:

• Find time zone from IP address
• How to determine a zip code and city from an IP address?
• Mapping US zip code to time zone
• Determine a User's Timezone
• Geocode an IP address?