DataTime dt = DataTime baru (); // dt 为时间 DataTime 对象
dt.tostring (); // 2005-11-5 13:47:04
dt.addyears (1) .tostring (); // 2006-11-5 13:47:04
dt.adddays (1.1) .tostring (); // 2005-11-6 16:11:04
dt.addhours (1.1) .tostring (); // 2005-11-5 14:53:04
dt.addmilliseconds (1.1) .tostring (); // 2005-11-5 13:47:04
dt.addmonths (1) .tostring (); // 2005-12-5 13:47:04
dt.addseconds (1.1) .tostring (); // 2005-11-5 13:47:05
dt.addminutes (1.1) .tostring (); // 2005-11-5 13:48:10
dt.addticks (1000) .tostring (); // 2005-11-5 13:47:04