No, we cannot. It is impossible to give a hard guarantee that a package will arrive on or before a certain date. There are so many things which we cannot control between our warehouse and the destination. Our warehouse staff hands over the package to the courier service, but the courier service may hand it over to another service. Perhaps your package has to cross a country border, or maybe even pass customs.
Orders which are placed before 2 PM CET (Central European Time) are handled and shipped with BPost the same day. The conditions which apply are that all articles must be in stock (see the FAQ on Backordered items) and that the order is paid electronically. We cannot guarantee same day shipments on orders which arrive after 2 PM (CET). Orders are treated on business days (i.e., Monday to Friday, except public holidays). Orders which arrive on a public holiday or in the weekend are handled the next business day.
We can tell when a package gets shipped, but we cannot guarantee when it will arrive.