Getting the client’s time zone (and offset) in JavaScript

Using an offset to calculate Timezone is a wrong approach, and you will always encounter problems. Time zones and daylight saving rules may change on several occasions during a year, and It’s difficult to keep up with changes. To get the system’s IANA timezone in JavaScript, you should use  Run code snippetExpand snippet As of September 2019, … Read more

How to initialize a JavaScript Date to a particular time zone

Background JavaScript’s Date object tracks time in UTC internally, but typically accepts input and produces output in the local time of the computer it’s running on. It has very few facilities for working with time in other time zones. The internal representation of a Date object is a single number, representing the number of milliseconds that have elapsed since 1970-01-01 … Read more

Mapping US zip code to time zone

I just found a free zip database that includes time offset and participation in DST. I do like Erik J’s answer, as it would help me choose the actual time zone as opposed to just the offset (because you never can be completely sure on the rules), but I think I might start with this, and have … Read more