As a traveller, you can change the dates of your travel from a conversation.
In the conversation with your host, you simply have to click on the 3 vertical dots and select "Edit the NightSwap"
You can also edit the number of travellers.
To save the updated data, click on "Edit your request".
NB: Before changing the data of your trip, nightSwapping recommends that you first discuss this with your future host so that they agree with the alterations you wish to bring.