'Day' in the Bible

for your fellowship in furtherance of the gospel from the first day until now;

being confident of this very thing, that he who began a good work in you will perfect it until the day of Jesus Christ:

so that ye may approve the things that are excellent; that ye may be sincere and void of offence unto the day of Christ;

holding forth the word of life; that I may have whereof to glory in the day of Christ, that I did not run in vain neither labor in vain.

circumcised the eighth day, of the stock of Israel, of the tribe of Benjamin, a Hebrew of Hebrews; as touching the law, a Pharisee;