Morning in America could, someday soon, be earlier than ever imagined.

President-elect Donald Trump vowed to end daylight savings time, a surprising pledge that, if carried through, would dramatically alter U.S. life in spring and summer months when Americans revel in sunshine well into traditional nighttime hours.

Daylight savings time tends to push sunshine to later hours, making for gloriously long, bright days in spring and summer months. Standard time brings more sunshine to earlier…