When you realize you’re in “good days” the feeling is called bittersweet. Therefore one should make the most, as soon as you realize the time is bittersweet. This helps prevent regrets of “not doing enough” later. Like today, it’s not too late to make the most of your upcoming weekend.
Rule of thumb: it will always get worse in some way, so you will always remember the past fondly, also because you usually tend to forget the bad parts.