Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This adds the ability to guess the user's timezone.
The guessing is based on the user offset and zone abbreviation over a handful of moments. We use Jan 1 and July 1 from the 2 years before and after the current year. We also do a binary search to find the exact time the user's timezone changed, and use moments just before and after the transition.
Once we have this data about the user's environment, we compare it to our known timezones. The timezone that is closest to the user's environment wins.
Due to links and timezones that appear similar in recent years, there are often a handful of timezones that appear to match. We maintain a list of approximate populations for each timezone's largest city, and use that as a tie-breaker.