var datatime1 = justep.xbl("dataMaster").getValue('F1');
var datatime2 = justep.xbl("dataMaster").getValue('F2');
var datatime3 = datatime1+ datatime2;
justep.xbl("dataMaster").setValue('F3',datatime3);
可以么
var datatime1 = justep.xbl('dataMaster').getValue('fTBJZRQ');
var datatime2 = justep.Date.increase(datatime1,30,'d' );
dataMaster.setValue("fYJHKRQ",datatime2);添加天数可以实现么