The phrase as of marks a specific point in time when information is accurate or when something takes effect. When a news report says “As of Monday morning, 15 inches of snow had fallen,” it means that's how much snow had accumulated by that exact moment. The amount might change later, but as of that time, the measurement was 15 inches.

You'll often see as of in official statements and reports: “As of January 1st, the new school policy goes into effect.” This tells you precisely when something starts or when the information was current.

The phrase helps prevent confusion about timing. If your teacher announces “As of today, your science project grades have been entered in the gradebook,” you know exactly when to check. If a sign says “Park closes at sunset, as of November 15th,” it means that's when the new closing time begins, not that the park closes on November 15th itself.

Think of as of as drawing a line at a specific moment: everything before that line might be different, and everything after might change, but at that exact point, here's what's true.