It's the RSPB's
Feed the Birds Day tomorrow (Saturday). So top up those feeders and bird tables, and make sure to put a little on the ground for birds that like to search for food on the ground like dunnocks. It's especially important at this time of year as birds use a lot of energy just in keeping warm.
PS current advice is not to use those fat balls which are wrapped in plastic mesh, as birds have been known to get hopelessly tangled in the stuff. There are more environmentally friendly and re-usable fat cake holders you can buy.