Web service - current time zone for a city? [closed]

Question

We encountered same issue and, alongside the great suggestions above, Google appears to have two complementary APIs, one for Time Zone from geocode (latitude/longitude) data and the geocode API.

For example, to get the time zone and offset for San Francisco:

1) Convert the city to a geocoded location:

http://maps.googleapis.com/maps/api/geocode/json?address=San%20Francisco,+CA&sensor=false

The geocoded location is in the JSON return data:

"location": {
    "lat":  37.77492950,
    "lng": -122.41941550
}

2) Convert the geocoded location to a local timezone and offset, if any:

https://maps.googleapis.com/maps/api/timezone/json?location=37.77492950,-122.41941550&timestamp=1331161200&sensor=false

Which returns the current time zone information:

{
          "status": "OK",
       "dstOffset":  0.0,
       "rawOffset": -28800.0,              
      "timeZoneId": "America/Los_Angeles",
    "timeZoneName": "Pacific Standard Time"
}

Time zones for a region can change for a variety of reasons. So it is a good idea to find an authoritative server-based solution and not cache. For more information see Wikipedia's Time Zone article.

earthtools.org provides a free web service to get the time zone from a city here:

http://www.earthtools.org/webservices.htm#timezone

You just pass in the long/lat values like this: (This is for New York)

http://www.earthtools.org/timezone-1.1/40.71417/-74.00639

---

EDIT:

It seems like earthtools has been shut down. A good alternative (That did not exist in 2008 when this question was answered) is the Google Time Zone API. To use it you must first activate the Time Zone API on your account. It is free if you stay below these limits:

• 2500 requests per 24 hour period.
• 5 requests per second.

The documentation is available on Google Developers.

Geonames.org has a wonderful set of worldly data that's available via webservice or download:

http://www.geonames.org/export/ws-overview.html

In particular

http://www.geonames.org/export/web-services.html#timezone

.

Earthtool's timezone info is not up to date ... for an instance, the Sri Lankan current offset is +5.5 from GMT but EarthTools shows as +6 which was the old offset before 2005.

I suggest GeoNames.org.

WorldTimeServer.com has what appears to be a comprehensive time zone database, which you can purchase access to in a variety of formats, including a .NET component for Web use.

No connection, just had to research the same thing myself recently.

Simple Offline Library : APTimeZones

In order to find the time zone for a location you can use such as the Google Maps API’s time zone API. Unfortunately this requires you to query a remote service and you are subject to their limits.

Here’s a library rom Alterplay called APTimeZones(Git is attached) that allows you to extract an NSTimeZone from a given location without the need to connect to a remote service. APTimeZones works by querying a local listing of time zones (included with the library).

In case anyone should bump into this question.

• You could use Google API to search for an address. That returns latitude / logitude. With those values in hand, you can find the closest timezone using e.g. PHP.

• Or you can use an API like timezoneapi.io (I'm behind that) which enables you to search for an address / city / country. It returns the address, the timezone information and the current date/time for that given timezone.

https://timezoneapi.io/developers/address