What is your favorite time of day to practice and why?

Early morning for me. Coffee, guitar! 

I'm a morning person every morning because I can do that to start my day. I have energy it puts me in the right mood for my work day and I make progress. I'm not always consistent when I come home from work but when I do I really love it too. On the weekends I stay with the morning routine but then also sometimes I just play for an hour or longer, here and there, throughout the day on the weekend. If I waited for the weekends, I wouldn't make as much progress or enjoy myself nearly as much. Thanks for the question!

This is a good question.  I've been thinking about it and here it is:  

I practice short exercises throughout the afternoon, then I'll go to a favorite piece.  I have to stop before 5 pm to let my muscles relax or they'll tighten up at 3 AM.  I am a senior player so I don't have the pleasure to practice in the late hours of the night (I've tried it).  I usually start at 1 pm, practice for 20-30 minutes, then take 10 minutes breaks or so after each session.  What I am really trying to achieve is "ease of action", stated by Ricardo Iznaola as well emphasize by many teachers.  That's about it.  

Until a whole-note later, I'll see you folks.

I suffer from chronic tendinitis, so I warm up my hands with electric gloves while going through my email, which usually takes the whole morning.

With work it is difficult. I don't have enough hours in the day. So I start practice at 7am through to 830am week days (a little later on weekends). I might be able to squeeze in some scales work or trouble-spot reviews for 30 mins around lunch time and, if i'm lucky, an hour before bed.

Late at night is my favourite time when I want to relax with my guitar. It’s quiet in the house with no distractions. Sometimes I will practice in the morning before lunch on days when I work afternoons. So practice time depends on my work schedule. 

Hi. I practice several times per day in short sessions. When I work on a new piece, that will be in the evening when the pets are quiet. Some practices are longer than others and I never set a time or duration. Morning, lunch, afternoon and evening are all good and I notice I play better or smoother as each short practice progresses. 

I prefer mornings when I am fresh and it puts me in a good mood for the day. If I practice at night I am often tired so am much freer in my choice of what I play to keep me motivated and energy levels up.

I'm a night owl. I prefer to practice at night when everyone is sleeping and I can connect myself with the universe through my guitar. 

For me, it's early morning.

When I play at different times of the day I do notice it's easier at night. It's more difficult in the morning. Usually try to play various times during the day or week to keep it interesting.

I'm up at 4:30 for coffee and a little screen time. My main practice routine runs from 5-7. Depending on the day, I can usually fit in another hour or two after that spread through the day. 

I start reading my email and news after breakfast with my hand in an electric glove to warm it up. I am a long-time tendinitis sufferer. Then I will have another session after dinner.