If you know throughout the day you will need the peace of mind that comes with meditation I think it's better to start the day with meditation. If you find yourself needing to meditate at any other point in the day you can always meditate again :). Meditation at the end of the day could clear your mind for a peaceful sleep though. Basically as long as you're meditating I think you're doing good.
It depends. I like to meditate in the morning and at night for different reasons. I can sometimes be overwhelmed or anxious for what the day brings, so meditating and letting this stress go is really helpful. At night my mind could still be racing, and meditation is a nice way for me to calm down, for a much needed sleep. It all depends on what you need.
Often, I feel tired at the end of the day, and meditation as an act of selfawareness it's kinda exhausting, so in order to make the most of it I rather do it at mornings