> use test switched to db test > version() 4.2.8 > db.test.find({}) {{ { "_id" : ObjectId("5efbaba4250838017f12c045"), "dateString" : "2006-01-02T15:04:05.123456789Z" } }} > db.test.aggregate( [\{$project: {date: {$dateFromString: {dateString: '$dateString'}}}}] ) 2020-06-30T14:22:04.013-0700 E  QUERY    [js] uncaught exception: Error: command failed: { "ok" : 0, "errmsg" : "Error parsing date string '2006-01-02T15:04:05.123456789Z'; 0: passing a time zone identifier as part of the string is not allowed '2'", "code" : 241, "codeName" : "ConversionFailure" } : aggregate failed : _getErrorWithCode@src/mongo/shell/utils.js:25:13 doassert@src/mongo/shell/assert.js:18:14 _assertCommandWorked@src/mongo/shell/assert.js:583:17 assert.commandWorked@src/mongo/shell/assert.js:673:16 DB.prototype._runAggregate@src/mongo/shell/db.js:266:5 DBCollection.prototype.aggregate@src/mongo/shell/collection.js:1012:12 @(shell):1:1 > db.test.aggregate([{$project: {date: {$dateFromString: {dateString: {$substrBytes: ['$dateString', 0, 28] }}}])}} {{ { "_id" : ObjectId("5efbaba4250838017f12c045"), "date" : ISODate("2006-01-02T15:04:05.123Z") } }} > db.test.aggregate([{$project: {date: {$dateFromString: {dateString: {$substrBytes: ['$dateString', 0, 29] }}}])}} 2020-06-30T14:21:22.393-0700 E  QUERY    [js] uncaught exception: Error: command failed: { "ok" : 0, "errmsg" : "Error parsing date string '2006-01-02T15:04:05.123456789'; 0: passing a time zone identifier as part of the string is not allowed '2'", "code" : 241, "codeName" : "ConversionFailure" } : aggregate failed : _getErrorWithCode@src/mongo/shell/utils.js:25:13 doassert@src/mongo/shell/assert.js:18:14 _assertCommandWorked@src/mongo/shell/assert.js:583:17 assert.commandWorked@src/mongo/shell/assert.js:673:16 DB.prototype._runAggregate@src/mongo/shell/db.js:266:5 DBCollection.prototype.aggregate@src/mongo/shell/collection.js:1012:12 @(shell):1:1 > ISODate('2006-01-02T15:04:05.123456789Z') ISODate("2006-01-02T15:04:05.123Z") > Date('2006-01-02T15:04:05.123456789Z') Tue Jun 30 2020 14:23:41 GMT-0700 (PDT) > db.test.updateOne({_id: ObjectId('5efbaba4250838017f12c045')}, {$set: {'dateString': '2006-01-02T15:04:05.12345678Z' )}} {{ { "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 } }} > db.test.aggregate( [\{$project: {date: {$dateFromString: {dateString: '$dateString'}}}}] ) {{ { "_id" : ObjectId("5efbaba4250838017f12c045"), "date" : ISODate("2006-01-02T15:04:05.123Z") } }} > db.test.updateOne({_id: ObjectId('5efbaba4250838017f12c045')}, {$set: {'dateString': '2006-01-02T15:04:05.123456789Z' )}} {{ { "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 } }} > db.test.aggregate( [\{$project: {date: {$dateFromString: {dateString: '$dateString'}}}}] ) 2020-06-30T14:37:05.058-0700 E QUERY [js] uncaught exception: Error: command failed: { {{ "ok" : 0,}} {{ "errmsg" : "Error parsing date string '2006-01-02T15:04:05.123456789Z'; 0: passing a time zone identifier as part of the string is not allowed '2'",}} {{ "code" : 241,}} {{ "codeName" : "ConversionFailure"}} } : aggregate failed : _getErrorWithCode@src/mongo/shell/utils.js:25:13 doassert@src/mongo/shell/assert.js:18:14 _assertCommandWorked@src/mongo/shell/assert.js:583:17 assert.commandWorked@src/mongo/shell/assert.js:673:16 DB.prototype._runAggregate@src/mongo/shell/db.js:266:5 DBCollection.prototype.aggregate@src/mongo/shell/collection.js:1012:12 @(shell):1:1 >