YOU SAID:

we would leave the christmas lights up until january

INTO JAPANESE

クリスマスは1月まで明かりをつけたままにしておく

BACK INTO ENGLISH

Leave the lights on until January for Christmas

INTO JAPANESE

クリスマスは1月まで明かりをつけておく

BACK INTO ENGLISH

Keep the lights on until January at Christmas

INTO JAPANESE

1月のクリスマスまで明かりをつけておく

BACK INTO ENGLISH

I'll keep the lights on until Christmas in January.

INTO JAPANESE

１月のクリスマスまで明かりをつけておきます。

BACK INTO ENGLISH

I will keep the lights on until Christmas in January.

INTO JAPANESE

１月のクリスマスまで明かりをつけておきます。

BACK INTO ENGLISH

I will keep the lights on until Christmas in January.