Web service - current time zone for a city?

Question

Is there a web service of some sort (or any other way) to pull a current time zone settings for a (US) city. For the parts of the country that don't follow the Daylight Saving Time and basically jump timezones when everyone else is switching summer/winter time... I don't fancy creating own database of the places that don't follow DST. Is there a way to pull this data on demand?

I need this for the database server (not for client workstations) - there entities stored in the database that have City, State as properties. I need know current timezone for these entities at any moment of time.

score 74 · Answer 1 · edited Apr 07 '14 at 11:12

74

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.

edited Apr 07 '14 at 11:12

terales

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answered Feb 20 '13 at 19:33

Mike Davis

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Note, that you can pass non-English city name to the Google Geocode. – terales Apr 07 '14 at 11:04
How do you compute current location time with this Google Timezone result ? – Nicolas Thery Jun 08 '16 at 10:43
@NicolasThery Without looking at the API docs I'm guessing `rawOffset` is offset against UTC in seconds. So just add this value to a UTC timestamp and you're done. – piit79 Oct 29 '16 at 17:16
@NicolasThery Sorry, it looks like you actually have to add `dstOffset` plus `rawOffset` to your UTC timestamp. – piit79 Oct 29 '16 at 17:39
how to add a callback function here so it can be used on browser and avoid the cross domain security problem – fekiri malek Dec 22 '16 at 15:04

Espo · Accepted Answer · 2015-08-21T05:30:07.023

47

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.

edited Aug 21 '15 at 05:30

answered Sep 11 '08 at 06:43

Espo

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what if we do not know the latitude/longitude information for a city? – Raj Feb 25 '11 at 06:45
EarthTools is great but since a week it's offset by 4 min. Great but does not seem reliable. – Malartre Oct 18 '11 at 21:49
1

I add a few issues with http://earthtools.org especially when DST in involved. I would not recommend this webservice. I found http://www.timeanddate.com/ to be much more accurate, it is not free though. – Jérôme R Mar 07 '12 at 08:57
i agree, DST support is very poor :( – Patrick Oscity Mar 11 '12 at 11:48
I was using earthtools until I realized that they only have DST info for western Europe (and currently they say so on their page.) – sfink May 20 '15 at 23:25
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As of 2015-09-09 it's not working. My app is in danger. How irresponsible!! I know it was free, but how can they just shut it down like that. – AtanuCSE Aug 09 '15 at 10:38
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@Espo this API is No longer working , will you please provide any alternate option – nivritgupta Aug 24 '15 at 11:51
@AtanuCSE I had a Tasker task that pinged it every morning to get the sunrise/sunset data for that day, based on my GPS location. Last good response I got was July 22. – GalacticCowboy Sep 16 '15 at 22:14
link is broken now – bubakazouba Mar 30 '20 at 05:16

score 16 · Answer 3 · edited May 13 '12 at 05:11

16

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

.

edited May 13 '12 at 05:11

Michael Freidgeim

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answered Sep 11 '08 at 07:14

Eric

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However it doesn't allow to specify date,for which you want to find timezone offset – Michael Freidgeim May 13 '12 at 02:39
Hi... Thanks for the answer and it helps me a lot. I need to ask you whether daylight saving time is implemented in it? Let me know as i can't test it now? I need current time from lat long. – Sagar Rawal Dec 12 '12 at 10:01

score 7 · Answer 4 · edited Jun 24 '12 at 14:07

7

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.

edited Jun 24 '12 at 14:07

Steve

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answered Nov 24 '11 at 08:56

megazoid

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score 5 · Answer 5 · answered Sep 11 '08 at 06:43

5

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.

answered Sep 11 '08 at 06:43

TheoJones

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score 2 · Answer 6 · answered Jun 02 '14 at 12:23

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).

I've rewritten this library in Java, so you can use it on Android devices also: https://github.com/agap/llttz — aga, Oct 16 '14 at 13:37

score 1 · Answer 7 · answered Jan 05 '17 at 01:27

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

How updated is it kept? And does it provide timezone on the basis of Latitude and Longitude? — Riaz Raza, Mar 14 '19 at 12:55

score 0 · Answer 8 · answered Apr 26 '13 at 16:30

0

I know this is answered, but I am posting this answer as people might still find it useful - The selected answer does not work successfuly right now.

Google have their own service, which is very reliable and easy to use, and outputs info in JSON format. It even allows for specifying a custom time, e.g get the timezone in 02/02/2013 in Malta.

https://developers.google.com/maps/documentation/timezone/

answered Apr 26 '13 at 16:30

Karl Cassar

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how to use it on browser with call back function or so to avoid the cross browser issue – fekiri malek Dec 23 '16 at 03:37

Web service - current time zone for a city?

8 Answers8

1) Convert the city to a geocoded location:

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

Linked

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