I don't think it matters. Just try to take it at about the same time each day, but make it a time when it is convenient. I have always taken mine in the morning as part of my daily morning routine. A seven day pill box makes forgeting or doubling up on a dose very unlikely.
To your body itdoesn't matnter as far asI know , but to you it may. So pick a time that is most convenient.
I do 7pm (which is dinner time) but equally it could be first thing AM or bed time. For various reasons those times are bad for me, so its 7 ... also there is some flexibility too. If i am going to a movie i may take my pills early or late (like 5pm or 11pm).
Its not so time critical.
Even missing a dose is not critical, threads on that topic here
As the others have said, I don't think when you take it is important, but it's more about when it's convenient for you to take it. I take mine at 7:45 pm right after we put the kids to bed. I even have a daily alarm on my phone that goes off at 8 pm to remind me in case I somehow forgot my meds.
I really don't think that it's very time sensitive. I take mine at around 9 PM, at the same time that I usually get my wife's pills to her. With a slow, very long time for effectiveness, I don't think that a few hours either way makes much difference.
I find the anti-coagulation clinics are very hung up on seeing this as a PM medication. For over 20 years I have taken it in the AM and have been followed by the same "coumadin clinic" for the last 10 plus. They still refer to my next evening dose when recommending adjustments. I try to correct them, but sometimes I just don't worry about it and handle it at the next dose that I'll be taking the following morning.
I specifically asked this question when I started on warfarin and was told it does not make a difference. I did read an article that recommended you take your blood pressure medicine at night, since supposedly your blood pressure can be high in the morning when you wake up. http://www.health.harvard.edu/blog/...event-more-heart-attacks-strokes-201110253668