"三十一日" meaning in Japanese

{
  "etymology_templates": [
    {
      "args": {
        "1": "三%十%一",
        "2": "さん%じゅう%いち",
        "3": "日",
        "4": "にち",
        "t1": "thirty-one",
        "t2": "day"
      },
      "expansion": "三(さん)十(じゅう)一(いち) (sanjūichi, “thirty-one”) + 日(にち) (nichi, “day”)",
      "name": "com-ja"
    }
  ],
  "etymology_text": "Compound of 三(さん)十(じゅう)一(いち) (sanjūichi, “thirty-one”) + 日(にち) (nichi, “day”).",
  "forms": [
    {
      "form": "三十一日",
      "ruby": [
        [
          "三",
          "さん"
        ],
        [
          "十",
          "じゅう"
        ],
        [
          "一",
          "いち"
        ],
        [
          "日",
          "にち"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "sanjūichinichi",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "さんじゅういちにち"
      },
      "expansion": "三(さん)十(じゅう)一(いち)日(にち) • (sanjūichinichi)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Japanese entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese links with redundant alt parameters",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese links with redundant wikilinks",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms read with on'yomi",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with 4 kanji",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with non-redundant non-automated sortkeys",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with redundant sortkeys",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "langcode": "ja",
          "name": "Time",
          "orig": "ja:Time",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "thirty-first day of the month"
      ],
      "id": "en-三十一日-ja-noun-1Hr3YLQZ",
      "links": [
        [
          "thirty-first",
          "thirty-first"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "other": "さんじゅう・いちにち"
    },
    {
      "ipa": "[sã̠ɲ̟d͡ʑɨːit͡ɕiɲ̟it͡ɕi]"
    }
  ],
  "word": "三十一日"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "三%十%一",
        "2": "さん%じゅう%いち",
        "3": "日",
        "4": "にち",
        "t1": "thirty-one",
        "t2": "day"
      },
      "expansion": "三(さん)十(じゅう)一(いち) (sanjūichi, “thirty-one”) + 日(にち) (nichi, “day”)",
      "name": "com-ja"
    }
  ],
  "etymology_text": "Compound of 三(さん)十(じゅう)一(いち) (sanjūichi, “thirty-one”) + 日(にち) (nichi, “day”).",
  "forms": [
    {
      "form": "三十一日",
      "ruby": [
        [
          "三",
          "さん"
        ],
        [
          "十",
          "じゅう"
        ],
        [
          "一",
          "いち"
        ],
        [
          "日",
          "にち"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "sanjūichinichi",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "さんじゅういちにち"
      },
      "expansion": "三(さん)十(じゅう)一(いち)日(にち) • (sanjūichinichi)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "senses": [
    {
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        "Japanese compound terms",
        "Japanese entries with incorrect language header",
        "Japanese lemmas",
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        "Japanese nouns",
        "Japanese terms read with on'yomi",
        "Japanese terms spelled with first grade kanji",
        "Japanese terms spelled with 一 read as いち",
        "Japanese terms spelled with 三 read as さん",
        "Japanese terms spelled with 十 read as じゅう",
        "Japanese terms spelled with 日 read as にち",
        "Japanese terms with 4 kanji",
        "Japanese terms with IPA pronunciation",
        "Japanese terms with IPA pronunciation missing pitch accent",
        "Japanese terms with non-redundant non-automated sortkeys",
        "Japanese terms with redundant sortkeys",
        "Pages with 1 entry",
        "Pages with entries",
        "ja:Time"
      ],
      "glosses": [
        "thirty-first day of the month"
      ],
      "links": [
        [
          "thirty-first",
          "thirty-first"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "other": "さんじゅう・いちにち"
    },
    {
      "ipa": "[sã̠ɲ̟d͡ʑɨːit͡ɕiɲ̟it͡ɕi]"
    }
  ],
  "word": "三十一日"
}