From the whiteboard I go through a routine to have the students chant the days of the week after me.
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, and Saturday.
Then, I will make them sing a song about the Days of the week.
Sometimes, on advanced occasions, I will ask in Japanese... 日は英語で？ randomly, to quiz their minds.
This method is synonymous with how the Days of the Week are taught.
The months are spoken by me and repeated by students.
then a song is implemented, using the children's fingers... For January, they hold up 1 finger... For February, 2 fingers... March is 3 fingers... all the way to November, which both hands hold up 1 finger each to symbolize "11" and the same is done for December except one hand has two fingers up and it is symbolizing "12"
Almost all Japanese kids know their Months as
I am giving them another element to switch language in their brains...
by using the song and them using their fingers... (this method has been tested and proven over my many years of teaching) later, they will have no problem to just sing the song quietly and look at their fingers... then they will know, 10月 is "October".