When is Too Late, Too Late to Reply?

When it comes to responding to comments, I take it quite seriously. As long as its not a bot I tend to respond to all of them. Though my response times are not the best, I still do my best to get back to nearly every comment eventually. Sometimes I wait a few days to respond to comments, things come up and just do not have the time to kindly respond to nice comments and give a good insightful response. So I tend to wait until I have the time and respond in mass. Due to this it may take up days for me to respond. I always hope I do not offend by doing this, I am not ignoring. Just waiting for a good time to respond. So for you, what do you consider waiting too long? For me its over 7 days. I think at that point the commenter probably forgot or moved on from the comment. So I do my best to respond before that. Sometimes I respond in a day or two.. but have been up to a week before. So that is where I draw the line unless I honestly forgot about someones comment.