If you want to have constant day lengths, you can't make sunrise your reference. It's physically not possible. There are (almost) exactly 24 hours between each

If you want to have constant day lengths, you can't make sunrise your reference. It's physically not possible. There are (almost) exactly 24 hours between each solar noon. There aren't 24 hours between each sunrise, that's why it moves every day. You'd have to change your day length at least twice a year. Perhaps in the past this would have been ok, but today it's IMO definitely not worth the additional complication that comes from changing day lengths. edit: I didn't read parent comment properly. Updated my comment.