'Day' in the Bible

For of this I am confident, that He who has begun a good work within you will go on to perfect it in preparation for the day of Jesus Christ.

so that you may be men of transparent character, and may be blameless, in preparation for the day of Christ,

holding out to them a Message of Life. It will then be my glory on the day of Christ that I did not run my race in vain nor toil in vain.

circumcised, as I was, on the eighth day, a member of the race of Israel and of the tribe of Benjamin, a Hebrew sprung from Hebrews; as to the Law a Pharisee;