For the very early years of teaching the piano, I have recommended for students, especially beginners to practice for 5 to 7 minutes every day. I decided that this would be my recommendation simply because when I was a beginner piano student, I was told to practice between 5 and 7 minutes per day.
Hundreds of students and many years later, I haven’t changed my mind and its not because I am so fixed in my ideas that I’m not willing to change. The simple reason that I have stuck to this recommendation, is because I have seen for myself, over and over again, how as little as 5 to 7 minutes of practicing every day creates improvement.
What I am also saying, from a piano teacher’s point of view, is that I have seen more progress with 5 to 7 minutes of practice everyday, totaling 35 to 49 minutes per week, produces more results and greater progress than an hour practice the day before a piano lesson. This might not make numerical sense, however it is the combination of a small amount of concentrated practice and practicing regularly every day. Basically the concept of little and often is more productive than a long piano practice once and a while.
So there are a few reasons why I am explaining this to an audience of retirees who are motivated and who typically have the time to get in as much practice as they want. The first reason is that if you know what works well with a person who is short of time, then you can scale this up as much as you want and optimize your piano practices. Practicing regularly is just as important to your progress as doing some practice.
I get that retirees learning and playing the piano are doing so because they really want to play. Also typically retirees have plenty of time to practice but sometimes life can get busy for retirees too, especially when caring for someone who is sick, or helping a family member out or when they have volunteered with some sort of project and life gets busy. During those busy seasons, please know that continuing with as little as 5 to 7 minutes of practice every day will keep your progress on track (and it might serve as a good daily stress relief too).
What this doesn’t mean that if you miss the odd day here and there, it will impede your progress. The odd day not practicing will not harm your overall progress.
Obviously if you are sick and have been advised to stop practicing for a short while, then you do need to follow medical advice and after you are well you can then get back to your piano practice.