I can think of a few examples. This past Saturday I had a perfect day, as it was snowing from the time I woke up until around 2. My daughter was at my parents’, so I could relax and do whatever I wanted all day. It would have been nice if I could tell you I was extremly productive but I wasn’t. I just hung out, watched TV, played on computer. It was great.
I have had perfect days where I went window shopping in small villages, stopped for a cup of coffee, relaxing and pleasant.
I have had perfect days where I have been on vacation and done great vacation stuff, very memorable.
I have had perfect summer days, where I spent the day on the deck, reading and relaxing.
No perfect day includes work, but a perfect work day would be one where I am up on time at work on time, no stress all day, and shopping in the evening.