// server9289 - support objects as single arguments to expressions. var t = db.server9289; t.drop(); t.insert({date: ISODate('2013-08-14T21:41:43Z')}); // This would result in a parse error on older servers assert.eq(t.aggregate({$project: {year: {$year: {$add:['$date',1000]}}}}).toArray()[0].year, 2013);