My dad is 90 and has been struggling with dates. His memory is ... ok. But dates and his calendar are very tough for him. He has also been struggling with text messages.
My sisters and I got him his Memoryboard for Father's Day, and he loves it. In fact, he likes it so much that he mentions it to each of us anytime we talk.
It has eliminated the "What day is today?", "When is that dinner?", "What time are you picking me up?", "When is XXX birthday?" type questions he's been asking for a couple of years now. He feels in control again because he is reminded of things and doesn't have to ask.
If you are not sure about getting a Memoryboard for your loved one, we can only tell our story. In our case, it has been fantastic.