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.
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:
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.
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.