The calendar in Desmedt's office is set as Monday but the 14th of December which was 2015 unlike the calendar in Ingrid's office set as a Tuesday 20th December 2016.
John tells Mrs Tinghe that her husband died 3 days ago on Friday which means today is Monday but, in an earlier scene, Mrs Sneyers changes her calendar to Dinsdag (Tuesday) December 20 2016.