Winter hrs. in D.C.

EST

Think of the time zone abbreviation used when the nation's capital is three hours ahead of Los Angeles during the colder months.

"Winter hrs. in D.C." refers to the time zone abbreviation used in Washington, D.C. during winter, which is Eastern Standard Time (EST). The clue plays on the common crossword shorthand "hrs." for "hours" to hint at a time-related answer. Since D.C. observes EST in the colder months (before switching to EDT in summer), the answer is simply the three-letter abbreviation.