'Day' in the Bible

Because of your help in giving the good news from the first day till now;

For I am certain of this very thing, that he by whom the good work was started in you will make it complete till the day of Jesus Christ:

So that you may give your approval to the best things; that you may be true and without wrongdoing till the day of Christ;

Offering the word of life; so that I may have glory in you in the day of Christ, because my running was not for nothing and my work was not without effect.

Being given circumcision on the eighth day, of the nation of Israel, of the tribe of Benjamin, a Hebrew of Hebrews; in relation to the law, a Pharisee: