"That ye may approve things that are excellent; that ye may be sincere and without offence till the day of Christ." (Phillipians 1:10)
The day of Christ
"One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind. He that regardeth the day, regardeth it unto the Lord; and he that regardeth not the day, to the Lord he doth not regard it..." (Romans 14:5-6b)
Now, Paul is referring to the keeping (or not) of the Sabbath. Something that isn't necessarily required depending on how and where you met Jesus. Jesus is "the Lord also of the Sabbath." (Mark 2:28) He said so Himself.
The so-called "Blue Laws" are still in effect in parts of America. Where it's illegal to work, buy, sell, etc. on Sunday. It's funny how Saturday is actually the end of the week, though, and Sunday's its beginning (Saturday's technically the Sabbath). However, should you work through the observance of the Sabbath to where you really don't regard the keeping of a certain day--as Paul is referring to in the above passage--consider another more important "day": The "day of Christ".
Only going around once
Some Christians are gung-ho for The Rapture. Others decry it as a devil's lie (which is stupid, in my opinion--preach for something, not against). There are those denominations who are actively looking for "Thy Kingdom come...on earth as it is in Heaven" (don't forget "Thy will be done" Matthew 6:10) and don't really care when or how Jesus returns. There are numerous shades across this spectrum and in all things--"approv[ing] things that are excellent"-- I believe that a traveling-light paradigm is the order of the day.
"We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts:" (2 Peter 1:19)
Jesus is spoken of above as the "day star aris[ing] in your hearts". Peter knows what he's talking about. He's referring to Jesus becoming real to you in your heart before you worry one whit about how or when or if He's coming back (He is, He said as much; see John 21:23 et. al.). Because waiting for Christ means so much more than merely "looking busy". Waiting on Him, day-in and day-out, where it gets ingrained into the fiber of your being, is simply about "looking" for Him. It's about sitting at His feet (see Luke 10:42) and also walking with Him, about coming unto Him (see Matthew 11:28-30). It's about knowing Him, now. Not any other time but now. This is what tells. This is how one is "ready". What are we waiting for?
"And now, Lord, what wait I for? my hope is in Thee." (Psalm 39:7)
In closing, the word "sincere" in the top verse has the Greek connotation of "judged by sunlight". Let the light of God shine on you by taking your life and all its constituent parts to Jesus. That there is enough for one lifetime. You'll be so busy walking and talking and enjoying the Lord that you won't really care about then, all you'll really care about is now. And Him. And not in that order.