"a la caída del sol" meaning in Spanish

{
  "head_templates": [
    {
      "args": {},
      "expansion": "a la caída del sol",
      "name": "es-adv"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "at sundown"
      ],
      "id": "en-a_la_caída_del_sol-es-adv-75d2ESE3",
      "links": [
        [
          "sundown",
          "sundown"
        ]
      ]
    }
  ],
  "word": "a la caída del sol"
}

{
  "head_templates": [
    {
      "args": {},
      "expansion": "a la caída del sol",
      "name": "es-adv"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        "Spanish adverbs",
        "Spanish entries with incorrect language header",
        "Spanish lemmas",
        "Spanish multiword terms"
      ],
      "glosses": [
        "at sundown"
      ],
      "links": [
        [
          "sundown",
          "sundown"
        ]
      ]
    }
  ],
  "word": "a la caída del sol"
}