10月は神無月（かんなづき）ともいいます。日本語で神無月は「神の無い月」です。これは全国の神様が旧暦10月に出雲に集まり、他の地方から神がいなくなるからです。一方、出雲では神がいるので神在月（かみありづき）と呼ばれています。大変説明が難しいのですが、日本語では「無」は格助詞の「な」で「の」という意味から「神の月」すなわち神様を祀る月となります。しかし、長野県の諏訪地方周辺だけは例外で、神在月と称していました。これは元々、出雲は大国主大神が治めていましたが、天津神である建御雷神が大国主大神に国譲りを迫ったとき、息子の建御名方神が建御雷神との相撲に負け、諏訪地方に幽閉されたため、出雲に参集できなくなり神在月となったというものです。現在は諏訪の人でも神在月と称す事はほとんどないそうで、歴史の風化が危惧されます。
October is also called Kan-na-zuki (神無月). In Japanese, you write “神” for “Kan” and it means God (nothing religious). For “na” you write “無” which means none or doesn’t exist. For “zuki” you write “月” which means month. So all together, it was “a month without God”. This is because in the legend all the deities go to Izumo in Shimane prefecture in October, so the deities will be gone from other prefectures. Meanwhile, all the deities are in Izumo, so it is called “Kami-ari-zuki” there (“ari” means existing). It is very complicated to explain, but in Japanese “na, 無” can also work as a case-marking particle, so it can mean “God’s month”. But there are exceptions in Suwa region in Nagano prefecture. They used to call October “Kami-ari-zuki” and there is a story why so it. There used to be Okuninusi-okami governing Izumo but when Takemikazuchi who is one of the deities from heaven asked him to offer the land, his son, Takeminakata fought Takemikazuchi by sumo wrestling. Takeminakata lost and got confined in the Suwa region. Because he is one of the deities and couldn’t go to Izumo in October, Suwa region was also called Kami-ari-zuki. But now, not much people know about this fact, so it is normally called Kan-na-zuki like all the other prefectures. It is worried that the Japanese history is fading away.
格助詞：case-marking particle、治める：govern、国譲り：land offering、迫る：ask、幽閉される：get confined、風化する：fade、危惧される：be worried