Off days are simply not a thing. You can either be like physically sick and in that case you take the day off but there are no off days. If you are good at something and you can do things in a single threaded manner with focus and you have one to two things which are major items that you want to check off, every single day will be a good day. Now you might not make as much progress or some days you might make a lot of progress, but the days in which you do not have progress are not off days.
I genuinely mean this with the greatest of respect when I say that’s terrible advice.
We are not machines. Some days we are going to be better at the same task than other days.
You see this with professional sports players and you see this with professionals in IT too.
Except in our jobs we often have the luxury of being able to focus on other activities on the off day. To use a sports analogy, it’s like playing the defensive game when your attacking game isn’t there that day.
But the most important thing one can do on an “off day” is to not push yourself too hard otherwise you’ll burn out and be “off” the following day too. That applies emotionally as well as physically. Don’t get upset that you’re struggling one day because tomorrow is a new day.
That's a robot's take. You can have days where you slept poorly or need a nap to get back on track or just lack motivation.
Personally I try to take on tasks that don't require as much brainpower. If I'm really too tired I'll just take a nap, because it's better to take a 20 minute nap and do work for the rest of the afternoon than feeling terrible and doing hardly anything for a whole afternoon.
