Which sects interpret "Day and Hour unknown" literally? “Watch therefore, for you know neither the day nor the hour in which the Son of Man is coming.
  Matthew 25:13 (NKJV)


Is there any Christian sect which literally interprets this verse and says that even if there is no way of knowing the exact day or hour, there are some clues available from the scripture to calculate or know the season, year or century when Jesus will come again? If so, what is the basis of their calculations or arguments?
I would argue that most churches accept this quite literally, and that the exceptions prove the rule.

Three great examples in the last 150 years of trying to pick a date are as follows:


The Millerites who, in following Miller, were convinced Jesus was coming back in 1844.
Ed Whiseant's "88 Reasons the Lord is Coming Back in 1988"
Harold Camping's date of May 21, 2011


In all cases, these predictions did not come to pass. (I realize that since all three dates have come to pass, this may come as a shock to some people - but so far the record is zero :)

In at least the later two cases, most Protestants dismissed the prophecies as heresy, using precisely the justification you state.  Here, for example is a post from March 2011, using precisely the same justification.

The most interesting of the three, however, is clearly that of the Millerites. Like Camping, William Miller stuck his neck out and said the Lord was coming back in 1843.  When that didn't happen, he recalculated and figured out it was 1844.  When that discredited him, he slipped off the stage - but not before providing the essential ingredients to help launch the Seventh Day Adventists and the Jehovah's Witness.

But again, these are hardly indicative of the mainstream.  Most of us just say, "Really?"