Cheer Up the Lonely Day is an opportunity to make a lonely person happy. Any time you can make someone happy, you've done a good thing, and should be proud of yourself.
Lonely people have few friends and loved ones. They may have lost loved ones over the years. They may be elderly. They see people on an infrequent basis.
Spend some time today cheering up lonely people. It's easy to do.....just spend some time with them. When you visit, bring happy things to talk about. Keep the conversation upbeat, and lively. When you leave, give a big hug and let them know you enjoyed the stay. Sending cards or making a phone call is okay, only if they live too far away to visit. What a lonely person really needs, is face to face time with other people.