Highest Echelon

The official spelling is Daylight Saving Time, not Daylight SavingS Time.

Saving is used here as a verbal adjective (a participle). It modifies time and tells us more about its nature; namely, that it is characterized by the activity of saving daylight. It is a saving daylight kind of time. Similar examples would be a mind expanding book or a man eating tiger. Saving is used in the same way as saving a ball game, rather than as a savings account.

In the U.S., restaurants and bars have various closing policies. In many states, liquor cannot be served after 2:00 a.m. But at 2:00 a.m. in the fall, the time switches back one hour. So, can they serve alcohol for that additional hour in October? The official answer is that the bars do not stop serving liquor at 2:00 a.m., but actually at 1:59 a.m. So, they have already stopped serving when the time changes from Daylight Saving Time into Standard Time. In practice, however, many establishments stay open an extra hour in the fall.