Hey Yerbol
I think you will need to change the way it is saving the dates.
This is pretty simple really but it because of the way MySQL can search (and order) dates.
A timestamp is a valid time format, and MySQL knows how to sort this.
The format of YYYYMMDD is also a valid date, but it is also a number – which can be used for sorting.
With the dots in between:
DD.MM.YYYY
you actually have a string, a string cannot be searched by MySQL efficiently as date, this field will first need to be transformed to something understandable by MySQL otherwise its not possible.
Hope that makes sense.
Thanks