Both have advantages.
The benefits of showering in the morning
If you have a busy day ahead of you, it is best to shower in the morning. Many good ideas are born in the shower. It can be helpful if you get your ideas early in the day. Sometimes you need some time to process the ideas. The real aha moment will hopefully come in the middle of the day, exactly when you can put it to good use.
Read also: Why do good ideas arise in the shower and at other unexpected moments?
The benefits of showering at night Do you still have a lot of energy right before going to bed? Then the right time to shower for you might be in the evening. The warm shower increases your body temperature, after the shower your body temperature decreases again, a process that prepares your body to go to sleep.