Scripture tells us in Genesis 1:14 that He gave us the sun, moon, and stars for signs, for appointed times (the original word here is mo’ed which means appointed times) for days and for years. Thus He set His calendar in the sky where no man could adjust it.
This video uses an excerpt out of the passion for truth video which was looking a the Sabbath day. Interestingly, Jim Stanley recognises the verse, but is unable to see the truth he holds.
Jim refers to the appointed times as a signal as appointed beforehand – This video covers this issue, that the signs are given before the event.
Jim also refers to the signs of the second coming, which are seen in Revelation 12. Specifically these are the signs of the tribulation. I have posted more information about that here.