During the evening you may experience slowdowns due to everyone being online at that time, so things that require a high bandwidth may not work very well during those times. For me (EST) the peak time is usually somewhere around 7:30PM or so to 11:30PM or so.
You could always still set up the account at testmy.net (which is much more helpful than running the tests without an account) and run just a few tests using the protocols mentioned (12MB for download, 2MB for upload), but with the router in the mix. This isn't the normal procedure, but it still might help a little. I wouldn't run a lot of them, but it might not hurt to run two or three. Again, though, please set up the account before doing them. It just gives a lot more info than if run under no account. Not personal info, but test info, including specifics and patterns, plus the account keeps the results all in one place.
Chris ran one earlier, remotely, right in the midst of peak time, and the speed was great.