CFLib.org – Common Function Library Project

Description:
Similar to DateConvert, but provides local2zone and zone2local conversion from one time zone to another.

Return Values:
Returns a date/time object.

Example:

<cfset todayPST = Now()>
<cfset todayGMT = DateConvertZ("local2zone", todayPST, "GMT")>
<cfoutput>
The Time in PST: #TimeFormat(todayPST,"HH:mm:ss")#<br>
Converted to GMT:#TimeFormat(todayGMT,"HH:mm:ss")#
</cfoutput>

Parameters:

Full UDF Source:

/**
 * Similar to DateConvert, but provides local2zone and zone2local conversion from one time zone to another.
 * 
 * @param conversionType      Conversion type to use.  Options are zone2local (date object is from the specified time zone and this will convert it to local time) and local2zone (date object is based on local server time and this will convert it to the specfied time zone.):   
 * @param dateObj      Date object you want to convert. 
 * @param zoneInfo      Standard time zone abbreviation as well as standard plus mod such as PST-8. 
 * @return Returns a date/time object. 
 * @author Chris Wigginton (cwigginton@macromedia.com) 
 * @version 1, November 26, 2001 
 */
function DateConvertZ(conversionType, dateObj, zoneInfo)
{
  var targetZone = "";
  var targetSpan = 0;
  var targetDate = "";
  var utcDate = "";
  var hourDiff = 0;
  var minDiff = 0;
  var zoneModOffSet = 0;
  var zoneMod = 0;
    
  //timeZone object
  var timeZone = StructNew();
  timeZone.UTC  =   0;     // Universal Time Coordinate or universal time zone
  timeZone.GMT  =   0;     // Greenwich Mean Time same as UTC
  timeZone.BST  =   1;     // British Summer time
  timeZone.IST  =   1;     // Irish Summer Time
  timeZone.WET  =   1;     // Western Europe Time
  timeZone.WEST =   1;     // Western Europe Summer Time
  timeZone.CET  =   1;     // Central Europe Time
  timeZone.CEST =   2;     // Central Europe Summer Time
  timeZone.EET  =   2;     // Eastern Europe Time
  timeZone.EEST =   3;     // Eastern Europe Summer Time
  timeZone.MSK  =   3;     // Moscow time
  timeZone.MSD  =   4;     // Moscow Summer Time
  timeZone.AST  =  -4;     // Atlantic Standard Time
  timeZone.ADT  =  -3;     // Atlantic Daylight Time
  timeZone.EST  =  -5;     // Eastern Standard Time
  timeZone.EDT  =  -4;     // Eastern Daylight Saving Time
  timeZone.CST  =  -6;     // Eastern Time
  timeZone.CDT  =  -5;     // Central Standard Time
  timeZone.MST  =  -7;     // Mountain Standard Time
  timeZone.MDT  =  -6;     // Mountain Daylight Saving Time
  timeZone.PST  =  -8;     // Pacific Standard Time
  timeZone.HST  = -10;     // Hawaiian Standard Time
  timeZone.AKST =  -9;     // Alaska Standard Time
  timeZone.AKDT =  -8;     // Alaska Standard Daylight Saving Time
  timeZone.AEST =  10;     // Australian Eastern Standard Time
  timeZone.AEDT =  11;     // Australian Eastern Daylight Time
  timeZone.ACST = 9.5;     // Australian Central Standard Time
  timeZone.ACDT = 10.5;    // Australian Central Daylight Time
  timeZone.AWST =   8;     // Australian Western Standard Time
    
  //Check for +- timezone mod such as PST-4
  zoneModOffSet = FindOneOf("+-", zoneInfo);
  if(zoneModOffSet) {
    //Extract out the zoneInfo and zoneMod
    zoneMod = Val(Right(zoneInfo, Len(zoneInfo) - zoneModOffSet + 1));
    zoneInfo = Left(zoneInfo, zonemodOffSet - 1);            
  }
    
  targetZone = timeZone[zoneInfo] + zoneMod;
    
  // Grab Target Zone Info
  hourDiff = fix(targetZone);
  minDiff = (targetZone - hourDiff) * 60; 
    
  targetSpan = CreateTimeSpan(0, hourDiff, minDiff, 0);

  if (conversionType IS "local2zone") {
    // date is local time so convert it to utc first
    utcDate = DateConvert("Local2Utc", dateObj) ;
    // Add the target zone difference
    targetDate = utcDate + targetSpan;
    return "{ts '" & DateFormat(targetDate, "yyyy-mm-dd ") & TimeFormat(targetDate, "HH:mm:ss") & "'}";
  }
  else if (conversionType is "zone2local") {
    //date is in the target zone so convert it to utc first
    targetDate = dateObj - targetSpan;
    //convert it back from utc to local
    targetDate = DateConvert("Utc2local", targetDate);    
    return "{ts '" & DateFormat(targetDate, "yyyy-mm-dd ") & TimeFormat(targetDate, "HH:mm:ss") & "'}";
  }
  return "{ts 'yyyy-mm-dd HH:mm:ss'}"; // error return
}