When Is The Best Time To Do Yoga, Am Or

When is the best time to do yoga, am or pm? I go to work at 7am or 3am - at desk or printing and on my feet for 4 hours or more per day depending where I am working that day, I am a dc clerk with. Variety of jobs. I have exercise equipment and I am a gym member but only go for my spouse because I am not motivated. My spouse goes but does not continue after 6 months. I am 20 lbs over weight and need to stay focused though out the year so I want to try yoga to see if it will be the answer. I have never been on a long term diet and have plenty of energy ( more than most people at my age of 49) I just seem to get distracted .