When you have split cards, it is also possible to merge cards. When you click a card with your cursos 'fixed', you can clearly see which other cards on the board are related to this card.
You can place a card underneath each other on the same day, but it is also possible to put the card together. Drag the card to a related card. The card is animated to show that it can be 'dropped'. The cursos also adapts in terms of display.
Release the card (drop) to perform the action. Data of both cards will be saved and added if necessary. When you have activities and therefore also a 'duration', the duration of the cards is added together. The same goes for labels