Converting +between UTC and local time

Time zone ID +

Each time zone is uniquely identified by its time zone ID which is +a numeric reference or a name. The CTzId class encapsulates +a time zone identifier. A time zone ID is created using the CTzId::NewL() factory +method, for example:

_LIT8( KAsiaHongKong,"Asia/Hong_Kong" ); //A valid time zone name +CTzId* zoneId = CTzId::NewL( KAsiaHongKong );

The time zone’s +numeric ID or name can be retrieved using CTzId::TimeZoneNumericID() or CTzId::TimeZoneNameID() respectively. +

operator==() and operator!=() can +be used to check if the time zone ID matches or differs from another time +zone ID.

Converting +between UTC and local time

You can convert between times expressed +in UTC and local time using either the CTzConverter or RTz class. +

CTzConverter does the conversion on the client +side by caching rules which it gets from the time zone server. This class +should be used for conversion between UTC and local time for the system time +zone, for performance reasons.

If the conversion involves foreign +time zones, the RTz class can be used instead.

The +following types of time conversion are possible:

UTC +to local time in any time zone
UTC +to local time in the system time zone
Local +time in the system time zone to UTC
Local +time in any time zone to UTC

Setting the +local time

RTz::SetHomeTime() sets the local +time in the system time zone:

_LIT8( KMyTime, "20050105:103000.00" ); // Local time to set (5th January 2005 10:30 hrs). +TTime myTime( KMyTime ); //Create the time as a TTime object +TInt errCode = myTZoneServer.SetHomeTime( myTime );

The WriteDeviceData capability +is needed to set the system time.

Automatic UTC +offset

Whenever DST begins or ends, the UTC offset needs to be updated +accordingly. This can be done automatically by calling RTz::SetAutoUpdateBehaviorL(). +This function takes a value from the TTzAutoDSTUpdateModes enum. +When set to TTzAutoDSTUpdateModes::ETZAutoDSTUpdateOn(), +the UTC offset is automatically updated for changes to DST.