> db.sessions.update({}, {'_expiration_datetime': '2016-03-16T02:15:36.218Z'})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.sessions.find()
{ "_id" : "ddef7a4ac499fed695f910bc6df9984de3de73cb", "_expiration_datetime" : "2016-03-16T02:15:36.218Z" }
{ "_id" : "bbc95725191193a4e27c8d9e2f64c88bebb843f1", "_expiration_datetime" : ISODate("2016-03-16T02:15:37.933Z") }
{ "_id" : "8b094cd14f0e8b206fef3976fb310361a5964d34", "_expiration_datetime" : ISODate("2016-03-16T02:15:41.533Z") }
> db.sessions.find().forEach(function(data){data._expiration_datetime = new Date(data._expiration_datetime);db.sessions.save(data);})
> db.sessions.find()
{ "_id" : "ddef7a4ac499fed695f910bc6df9984de3de73cb", "_expiration_datetime" : ISODate("2016-03-16T02:15:36.218Z") }
{ "_id" : "bbc95725191193a4e27c8d9e2f64c88bebb843f1", "_expiration_datetime" : ISODate("2016-03-16T02:15:37Z") }
{ "_id" : "8b094cd14f0e8b206fef3976fb310361a5964d34", "_expiration_datetime" : ISODate("2016-03-16T02:15:41Z") }