On New Year's Eve, the speaker looks at the turning of the year and feels no thrill. Instead of a fresh start, the new year seems like a painted front, a stage prop, and behind it the same desert stretches on. Life is pictured as a barren landscape that doesn't change just because the calendar does.
The speaker sees people repeating familiar rituals: living, loving, playing, crying, welcoming births and burying the dead. Even the cheerful "Happy New Year" calls and messages feel routine, part of a play in which everyone pretends to take a fresh interest in what's new and says goodbye to what's old.
The ending softens the bleakness a little. We invent "oases," small comforts and hopes, because the alternative is worse: without them, mirages would become nightmares. The mood is weary, quiet and honest, though it also shows some sympathy for our need to pretend.