This is the 716th most frequent Hebrew word.
בימי
"In the days of" or "during the days of."
The word 'בימי' is used to refer broadly to days within a specific season.
בימי החורף לעיתים קרובות קר מאוד.
In winter days, it is often very cold.
The word 'בימי' refers to the days encompassed by a vacation period.
בימי חופש יש לי הרבה זמן לקרוא ספרים.
During vacation days, I have plenty of time to read books.
The word 'בימי' here indicates the period associated with childhood of the subject.