First of all, if you ask this question, it means that your grammar has not been learned well. Don't be angry.

For is (indicating time, distance, etc. ) here.

You can use for even if you don't have time later.

For example:

I have been in Beijing for three years.

You don't need the number of individual expressions at all, just how many times you can pull them.

For is only modified when the sentence wants to express some meaning.

I go to this supermarket four times a day.

Take this pill five times a day.

Don't die too much in learning English. Read more, study more and practice more. Let's go Merry Christmas.