Have you considered being a volunteer at a Veterans Administration Medical Center? Emphasis on volunteer not an employee with compensation. I do this two days a week for four hours each of those days. It allows me to be absent when traveling or around holidays, but is very interesting and fulfilling. There is an application process and you must pass a background check. If accepted the duties are to assist veterans or provide directions to locations in the center, various clinics or service areas.
Takes some time to learn your way around suffiently. In my case I had been receiving my health care at the facility so I already knew where many of the locations were. Most centers have employees responsible for those duties, called ambassadors, but there is always a need for more assistance. You might simply provide directions or assist in using facility map, but in some cases you may be called upon to transport a veteran with a wheelchair.
I am a disabled veteran but my conditions don't prevent me from assisting others. For me it is a way of giving back to fellow veterans while at the same time it is theraputic. Most days their I get the steps and exercise in that I would otherwise find it hard to motivate myself to achieve each day. As stated there is no monetary compensation for volunteers but the appreciation from the veterans as well as the ambassadors is sufficient.
Some days the only service I provide is a greeting or friendly conversation with another veteran. The kind words of appreciation or simply a nod of appreciation can be enough. Frankly, my wife appreciates me getting out of the house a while, especially during seasonal days that don't allow me to be out in my shop or doing yard work. Give it some thought. If it isn't a fit for you maybe one of your friends would find it just what they are looking for.