[CustomPress] Datepicker field stored in db in frontend format

I have a custom post type with a custom field, a date through the datepicker option. Looks nice.
I am using a filter plugin to select on this date. This filter plugin returns the results in ascending date order.
But... 10-03-2019 (March 10) comes before 24-02-2019 (Feb 24). Looking in the database, it turns out that the dates are actually stored in the format as shown on screen. To me, showing on screen and storing in the database are 2 different stories. In the database it should always be stored in yyyymmdd format.

The date in the filter plugin is used as start date, to filter the custom posts with date greater or equal this start date. That obviously won't work when the date is stored this way in the database.

Hence my question: can the date in the database be stored in yyyymmdd format, please?