Um... it does not predict the date that Jesus would enter Jerusalem. I assume you are referring to the passage in Zech. 9:9. Interestingly "Matthew" misread the original Hebrew of this passage and pictures Jesus riding into Jerusalem on two animals while the other Gospel writers who read the original passage correctly have him sitting on just one animal. Clearly Matthew was "fudging" historical events in order to get it to line up with how he misread prophecy. Not exactly the sign of divine inspiration is it? You can read more about this here:
http://www.geocities.com/b_r_a_d_99/twodonkeys.htm
As far as "fulfilled propehcy" is concerned how about some of the false prophecy that the NT gives in regards to the second coming?
See this link:
http://www.geocities.com/b_r_a_d_99/comingsoon.htm
And this also:
From the Skeptic's Annotated Bible:
The end will come within the lifetime of Jesus's listeners.
"Verily I say unto you, All these things shall come upon this generation." -- Matthew 23:36
One donkey or two? You're arguing over minor details, when the prophecy was amazingly fulfilled. I forget how the date thing works, but it was something like "a certain amount of time from this (whatever) point, the messiah will arrive..." Obviously way paraphrased. But he fulfilled it to the day.
Regarding the second coming, a lot of those are taken out of context.
"Verily I say unto you, This generation shall not pass away, till all be fulfilled." -- Luke 21:32
is
29 Then He spoke to them a parable: Look at the fig tree, and all the trees. 30 When they are already budding, you see and know for yourselves that summer is now near. 31 So you also, when you see these things happening, know that the kingdom of God is near. 32 Assuredly, I say to you, this generation will by no means pass away till all things take place. 33 Heaven and earth will pass away, but My words will by no means pass away.
...after an entire chapter describing the events and signs oof the end times.
"This" is referring to the generation in which those things happen.
Also, the Bible already knows what people will be saying:
2 Peter 3
1 Beloved, I now write to you this second epistle (in both of which I stir up your pure minds by way of reminder), 2 that you may be mindful of the words which were spoken before by the holy prophets, and of the commandment of us,[a] the apostles of the Lord and Savior, 3 knowing this first: that scoffers will come in the last days, walking according to their own lusts, 4 and saying, Where is the promise of His coming? For since the fathers fell asleep, all things continue as they were from the beginning of creation. 5 For this they willfully forget: that by the word of God the heavens were of old, and the earth standing out of water and in the water, 6 by which the world that then existed perished, being flooded with water. 7 But the heavens and the earth which are now preserved by the same word, are reserved for fire until the day of judgment and perdition of ungodly men.
8 But, beloved, do not forget this one thing, that with the Lord one day is as a thousand years, and a thousand years as one day. 9 The Lord is not slack concerning His promise, as some count slackness, but is longsuffering toward us,
not willing that any should perish but that all should come to repentance.