Honestly, the easiest way is to download a dedicated alarm app from the App Store. Apps like “Alarm Clock HD” or “Wake Up Time” work exactly like the one on your phone. They stay in the menu bar, and they even survive sleep mode if you adjust your power settings.
I tried “Alarm Clock HD” after my Calendar trick failed at 7:00 AM. Now I use it every day. It feels like cheating, but I’m okay with that.
Just be warned: some of these apps are ad-heavy and try to sell you premium features for “gentle wake-up sounds.” You don’t need that. Free versions work fine if you’re okay with a beep reminiscent of a 1990s microwave.