MongoDB

If you are working with Date or Mixed type objects in Mongoose you may notice that some objects are not always saved to the database, like they should, even if it looks like it just worked. The Dates and Mixed types in Mongoose, are not attached to Mongoose' change tracking system, which means for any changes you make to those fields, they have to be marked as changed. From the documentation on SchemaTypes: Built-in Date methods are not hooked into