You may need to retune your TV from time to time to receive new channels or due to engineering work at transmitters. In most cases retuning is straightforward and should only take a few minutes. Due to some work to the local transmitters you may need to retune your TV on the 27th February in order to continue to receive a signal.
Further details can be found here.
How to retune guidance can be found here.
This event is in the calendar.