I’ll explain why the first one is incorrect and the second one is accurate. Typically, we contrast since and for (as opposed to since and in, but that is another discussion). When indicating that something occurred in the past at a specific time, the words for and since are frequently used. Here’s how to keep it in mind:
Show four fingers. Add them up. If you’re able to count them, you can utilize for. Check your watch right now. (This is particularly effective if your watch has a calendar.) You should use since if you can see it on a watch or a calendar.