Tuesday-through-Thursday mornings remain the boring consensus for business audiences. But the honest reading of a decade of send-time studies is that the effect is small and YOUR list's pattern beats the global average.
Run the two-month test: alternate your send between two candidate slots and compare clicks (not opens. Privacy inflation). Most lists reveal a mild preference; few reveal a dramatic one.
What matters more than the hour: consistency (same rhythm builds the habit of expecting you) and hitting moments of relevance. The storm-season prep email the week storms start beats any perfectly-timed Tuesday.