German tells the time by counting towards the next hour, not back from the last one. halb acht is 7:30 — halfway to eight. That one word costs more learners an hour than anything else in A1.

⚠halb neun = 8:30, NOT 9:30. English says half past the hour just gone; German names the hour still to come. If a meeting matters, confirm with a number: „Also um acht Uhr dreißig?"