Detect and format the previous day's the_date()

I’m not sure how to easily explain this. On my site I am using the_date() to post the date once for everyday. I post a number of times a day and only want the date once to make it neat and tidy looking. What I want is a gap (maybe an hr or maybe just a bigger margin or whatever) between the final post of a day and the first post of the next day. Now this seems easy enough… just stick the gap formatting above the_date(). The problem is I don’t want this formatting above the very first date of the day, which of course will be the very top post, I only want the extra formatting above every date except todays. Does that make sense?

The site I want this for is my new site at wiseknowing.com. You see how the first post on the blog has a date. I *don’t* want formatting above that one. I’m happy as it is. But I *do* want formatting (a gap) above the other dates for previous days.

I have no training at php, but I can usually poke my way around in the WordPress files and figure things out. I have no idea where to start for this, however. Can anyone please offer me some help or a pointer on where to begin?

Thanks!
David