World Time Zone Database Subscription Service

World Time Server.com has become a valued destination on the Internet because of its comprehensive nature and because of the accurate world time data it provides.

You can now acquire the current database used on World Time Server.com to integrate in your company web site or in your own developed applications. Depend on our expertise to provide accurate world time data and get back to focusing on what you do best!

What You Get

When you subscribe to this data delivery service, we will send you:

1. Printed World Time Zone Guide. The printed edition of the Time Zone Guide provides a comprehensive list of over 495 time locations ordered by their political names as shown on World Time Server.com. The most important information provided is the Daylight Saving rules for each location, provided in three different formats - a general formula, actual start and end expressed in UTC, and actual start and end expressed in local time. (click here for more details on the printed Time Zone Guide)
2. Complete database in XML format and ASCII comma delimited format for easy import or direct use in any custom project development you create. (click for more info on the XML file or the ASCII file, including samples)
3. Username and Password for online updates which you can check for on demand for the duration of your one year subscription. We highly recommend checking at least quarterly for updates to the time zone data files to ensure your web site or application always has the most accurate information available.
4. Optional: Map Polygons. For each of the time zone locations in our database, we now have Map Polygons in KML format available. (click here to download a sample)  Polygons can be a valuable addition because they allow you to use Longitude/Latitude to pinpoint the matching time location. If you would like to view one example we came up with that uses these polygons in practice, click here!

What Does It Cost?

Our Premium Time Zone Database is available by subscription only through our parent company, Chaos Software Group, Inc. The subscription fee is $399.95 (US) per year.

Optional Addon - Map Polygons: The complete set of polygon files is an additional $100.00 (US) per year for our database subscribers.

How To Subscribe

1. Subscribe online using our secure order form (Available 24/7), or
2. Subscribe by phone at (972) 759-1121 (Agents are available between 8:30am - Noon and 1:00pm - 5:00pm, M-F in Dallas)

Any Questions?

We would be happy to answer questions about this subscription service. If there is some additional information you need that you cannot find on this site, please contact us!

Disclaimer

The information in this publication is subject to constant review due to changing government laws and regulations. Although every effort has been made to ensure the accuracy of this information, Chaos Software Group, Inc. and World Time Server.com shall not be held responsible for loss or damage caused by errors, omissions, misprints, or misinterpretation of the contents hereof. Furthermore, Chaos Software Group, Inc. and World Time Server.com expressly disclaims all and any liability to any person, whether a purchaser of this publication or not, in respect of anything done or omitted, and the consequences of anything done or omitted, by any such person in reliance on the contents of this publication.

 

Official Time Zone Guide in print

The printed edition of the Time Zone Guide provides a comprehensive list of over 495 time locations ordered by their political names, as shown on World Time Server.com. The most important information provided is the Daylight Saving rules for each location, provided in three different formats - a general formula, actual start and end expressed in UTC, and actual start and end expressed in local time. Each edition includes the complete and comprehensive list of each location in the world with their time zone rules.

Here is a sample listing from the current Time Zone Guide to give you a closer look at the information we provide for each location in our database:

The Title line of each record shows the Country Name, Region Name (if needed) and the Location ID in parenthesis. Region names are provided only if the country has more than one Time Zone. Location ID is a unique code given to each location, loosely based on the ISO 3166-1 list used by many organizations such as the United Nations.

Major Cities provides a list of a few of the largest cities by population in the region. This is not intended to be a complete list of all cities, but instead is a reference point to help determine if this time zone location is the one you are looking for. In the sample record above, Austin, Dallas, Houston and San Antonio are all listed as major cities in the region. What makes this city list useful is that there is also a second listing for Texas that includes the far west region of the state where the city of El Paso is listed. Unless you are familiar with the geography of Texas, you would not know which of the listings for Texas applies without the list of major cities to help define the region for you. Providing the map to the right of the time information is also intended for this same purpose.

Standard Bias is the mathematical representation of the difference between this location and UTC (Universal Time Co-ordinated). UTC is also known as GMT or Greenwich Mean Time or Zulu Time. Please keep in mind that UTC does not necessarily represent the local time in England or other locations on the Prime Meridian. Each location might have its own rules or adjustments, but UTC is always the same, as the standard by which time differences are measured.

If a location has a time adjustment for a portion of the year, known as Daylight Saving Time (DST), or sometimes as Summer Time, DST Bias will provide the mathematical representation of the difference between this location and UTC during the dates the adjustment is in effect. Otherwise, you may see a message to notify you that this location Does not observe DST and thus has the same time for the entire year without change.

For locations that do observe DST, you will be provided with a DST Start Formula and a DST End Formula to help you see the pattern, if any, to this location's time zone rules. Please note that there are some locations which do not have a regular pattern!

To avoid any confusion that the formula might cause, the actual day and time that this location will change its times are provided for both for this year and next year in both local time and UTC time.

 

XML File Details

One of the data formats provided with our Time Zone Database service is an XML formatted file. This XML file can be used within your project as the data source without requiring retyping of the information shown in this printed guide.

This XML file contains information about each Location, including pattern-based rules for Daylight Savings Time, where applicable. The fields or nodes used in the XML file to describe each location are:

1  Location ID	Unique Location code, based on ISO 3166-1 list used by the United Nations
2  Country	Name of Country
3  Region	Name of Region (used only if Country has more than one time zone)
4  Landmarks	Contains subnodes for <City>. Most locations have at least one city to provide the best known or most populated city or cities in this specific Region or Country
5  StdBias	Normal difference in hours and minutes of time in this location from UTC (+/-HHMM)
6  DstBias	If location supports Daylight Saving Time, difference in time of this location from UTC during dates DST is in effect, shown in hours and minutes (+/-HHMM)
7  DstStart	Rule for when Daylight Saving Time begins in this location, if applicable. If location uses DST and has a pattern which can be determined, this field shows the pattern as 0200 LST-SUN-MAR meaning at 02:00 am local time on the last Sunday in March.
8  DstEnd	Rule for when Daylight Saving Time ends in this location
9  StdName	Full local name for Time Zone when observing Standard Time
10  StdAbbrev	Local abbreviation for Time Zone when observing Standard Time
11  DstName	Full local name for Time Zone when observing Daylight Saving Time
12  DstAbbrev	Local abbreviation for Time Zone when observing Daylight Saving Time

Click here to view an sample of what the XML file looks like, to show some real examples of how these fields are used.

   

ASCII CSV File Details

One of the data formats provided with our Time Zone Database service is an ASCII delimited file. This ASCII file can be used within your project as the data source without requiring retyping of the information shown in this printed guide.

If you are unfamiliar with what an ASCII comma delimited text file or CSV file looks like, each location is on a separate line, with quotation marks at the beginning and end of each field and with commas separating the fields.

The first line of the CSV file contains the field names to define what data the rest of the file holds. These fields are:

1  Location ID	Unique Location code, based on ISO 3166-1 list used by the United Nations
2  Country	Name of Country
3  Region	Name of Region (used only if Country has more than one time zone)
4  City List	List of some major cities in this specific Region or Country
5  StdBias	Normal difference in hours and minutes of time in this location from UTC (+/-HHMM)
6  DstBias	If location supports Daylight Saving Time, difference in time of this location from UTC during dates DST is in effect, shown in hours and minutes (+/-HHMM)
7  DstStartPattern	Rule for when Daylight Saving Time begins in this location, if applicable. If location uses DST and has a pattern which can be determined, this field shows the pattern as 0200 LST-SUN-MAR meaning at 02:00 am local time on the last Sunday in March.
8  DstEndPattern	Rule for when Daylight Saving Time ends in this location
9  MapFile	Pertains to World Time Server web site only for map display
10  ThisYearDSTStart	In local time, actual day and time Daylight Saving Time begins in the current year
11  ThisYearDSTEnd	In local time, actual day and time this location will return to standard time
12  NextYearDSTStart	In local time, actual day and time Daylight Saving Time begins next year
13  NextYearDSTEnd	In local time, actual day and time this location will return to standard time
14  ThisYearUTCStart	In UTC time, actual day and time Daylight Saving Time begins in the current year
15  ThisYearUTCEnd	In UTC time, actual day and time this location will return to standard time
16  NextYearUTCStart	In UTC time, actual day and time Daylight Saving Time begins next year
17  NextYearUTCEnd	In UTC time, actual day and time this location will return to standard time

By the way, UTC refers to Universal Time Co-ordinated, also known as Greenwich Mean Time (GMT) or Zulu time. Local times around the world can be compared by the difference (or bias) between the each location and UTC. UTC time is not necessarily the time in any given country. For example, the United Kingdom will change its clocks for Summer Time or Daylight Saving Time for part of the year and during that period will be an hour off of UTC!

Click here for a sample of what the ASCII text file will look like.

   

World Time .NET component for Windows and Web projects

If you want to provide accurate local times on your own website or applications, we have included a special .NET component (ChaosSoftware.WorldTime.dll). This will allow you to simply query this object to get local times around the world, rather than creating a time project from scratch.

Requirements

• Microsoft .NET Framework 2.0 (.NET 1.1 version also available)
• ChaosSoftware.WorldTime.dll - a .NET component supplied free to World Time Data Subscribers
• worldtime.xml - one of the data files available with our World Time Data Subscription

Using the WorldTime .NET Component in ASP.NET

The worldtime component can take any time in UTC and a location and return to you the matching time in the specified location. Here is a basic walkthrough of using this component to retrieve and display a current time around the world.

First, you need to add the ChaosSoftware.WorldTime.dll to your project.

Second, before you can use any functions, you need to load the supplied WorldTime data into memory. If you plan to use the time functions often, you should likely put this in your Application Start area. Here is a sample from a Global.asax.vb file:

     Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
         ChaosSoftware.WorldTime.LoadData("c:\project1\worldtimedata\worldtime.xml")
     End Sub

With the data loaded you can now find the data for a specific location, then ask it to convert a UTC time to the local time of the location. Here is a sample:

     Dim ThisLocation As ChaosSoftware.WorldTime.Location
     Dim ThisLocalTime As DateTime
     Dim ThisDST As Boolean
     ThisLocation = ChaosSoftware.WorldTime.GetLocationData("US-TX")
     ThisLocalTime = ChaosSoftware.WorldTime.GetLocalTime(DateTime.UtcNow(), ThisLocation, ThisDST)

The value of ThisLocalTime in this sample will provide a converted local time as of right when the code executed. The Boolean value of ThisDST will also automatically be set as true or false based on whether this location is currently observing daylight savings time or not.

  

Function Documentation

LoadData
Parameters: XMLFileName
Purpose: To load your current worldtime.xml file into memory. You will need to supply a complete path where this file can be located.
Example:

     LoadData("c:\project1\worldtimedata\worldtime.xml")

GetLocationData
Parameters: LocationID
Returns: ChaosSoftware.WorldTime.Location (as defined below)
Purpose: Provide any Location in the WorldTime database and this function will retrieve all the information for this location in a strongly classed, ready to use object.

A Location object has the following attributes, all of which are strings:

• LocationID - the unique identifier for this location
• Country
• Region - this field is only used if the country has multiple time zones, usually a state or province name or other information to help describe the specific location
• CityList - a simple list of major cities found in this location
• StdBias - the offset from UTC used by list location
• DstBias - if empty, location does not use DST. If not empty, the offset from UTC used when DST is in effect
• DstStart - a pattern describing when DST starts in this location
• DstEnd - a pattern describing when DST ends in this location
• StdZoneName - the local name for the time zone of this location (which may not be unique worldwide!)
• StdZoneAbbrev As String - the local abbreviation for this time zone
• DstZoneName As String - the local name for the time zone when DST is observed
• DstZoneAbbrev As String - the local abbreviation for this time zone when DST is observed

  

GetLocalTime
Parameters: (BaseUTCTime (as DateTime), LocationData (as ChaosSoftware.WorldTime.Location), DST (as Boolean))
Returns: DateTime
Purpose: To return the LOCAL DATE and TIME from a UTC input. DST will return either True or False to indicate whether location is observing DST at the returned time

GetUTC
Parameters: LocalNow (as DateTime), LocationData (as ChaosSoftware.WorldTime.Location), DST (as Boolean)
Returns: DateTime
Purpose: To return the UTC DATE and TIME from a LOCAL TIME input. DST will return either True or False to indicate whether location is observing DST at the returned time

Decode_Date
Parameters: A DST pattern (as given in the DstStart or DstEnd for a Location), Year (as short number)
Returns: DateTime
Purpose: Converts a pattern into a specific day and time for a given year

GetCountryList
Parameters: none
Returns: SortedList
Purpose: Returns a SortedList suitable for assigning to a listbox or dropdownlist control with all the location names in the WorldTime Database

GetCountryListSelectedOnly
Parameters: SelectedList (as String - this should be a string of LocationID's separated by commas, such as "US-NY,US-CA,GB,AU-NSW" )
Returns: SortedList
Purpose: Returns a SortedList suitable for assigning to a listbox or dropdownlist control with all the location names for just the asked-for locations

IsValidLocationID
Parameters: PlaceToCheck (as String)
Returns: Boolean
Purpose: Determine if a potential location id is a valid current location in the database

GetRandomLocationID
Parameters: none
Returns: String
Purpose: Return a random LocationID

FindLocationIDs
Parameters: Field, SearchFor, InstrCompare, MultiHit
Returns: String (comma delimited list of LocationIDs)
Purpose: To locate the specific locations that match search criteria
Values:
  Field (String) = Which attribute of a location to search on. Possible values are

1. LocationID - use "locationid" or "1"
2. Country - use "country" or "2"
3. Region - use "region or "3"
4. City List = use "city" or "4"
5. Standard UTC Variance - use "stdbias" or "5"
6. Daylight UTC Variance - use "dstbias" or "6"
7. Daylight Start date and time (pattern) - use "dststart" or "7"
8. Daylight End date and time (pattern) - use "dstend" or "8"

  SearchFor (String) = Any Text or Number to search for.
  InstrCompare (Boolean, optional) = If false, then performs exact match search. If true, it performs an partial match search.
  MultiHit (Boolean, optional) = If false, then returns only first hit. If true, returns a comma delimited list.

License Info

This component is licensed to the subscribers to the World Time Database from WorldTimeServer.com. You will have the right to use this on ONE web server OR ONE application while you are a subscriber to the WorldTime Database from worldtimeserver.com. Should you desire to use this component for more than one project, you can contact our sales department for special pricing information for enterprise or site-wide use.

This component is currently in use on http://www.worldtimeserver.com if that speaks to our opinion of its suitability for our own use. However, we provide this component AS-IS and make no promise or warrant that this worldtime.dll will meet your requirements or that the operation of the software will be uninterrupted or error free. Nor do we offer any Warranties or Guarantees of any kind. You are free to use this dll within the terms of your licence in any way you see fit, but AT YOUR OWN RISK.

It is also not our intention to provide consulting, performance tuning nor technical assistance beyond the very fundamentals for this component.  We simply provide it as an option for the subscribers to our WorldTime Database Service, should you decide it is useful for your needs.