'Days' in the Bible

Then after three years I went up to Jerusalem to see Peter, and abode with him fifteen days.

Ye observe days, and months, and times, and years.

Believers, I beg of you, become as I am [free from the bondage of Jewish ritualism and ordinances], for I have become as you are [a Gentile]. You did me no wrong [when I first came to you; do not do it now].

And you know that in those early days it was on account of bodily infirmity that I proclaimed the Good News to you,

But as in those days he who had birth after the flesh was cruel to him who had birth after the Spirit, even so it is now.