This is the 863rd most frequent Latvian word.
septembra
"Septembra" is the genitive form of "septembris," meaning "of September" in English.
In this case, 'septembra' (also in the genitive form) is used to describe the time reference 'middle of September'.
Mūsu ceļojums notika septembra vidū.
Our trip took place in the middle of September.
Here, 'septembra' is used as genitive to show association with the year and month ('next year's September').
Mēs plānojam pasākumu uz nākamā gada septembra.
We are planning the event for next year's September.
Here, 'septembra' is the genitive form of 'septembris', indicating possession or association (beginning of September).