Hi Reaper
The Bible doesn't say anything about Ramadan because the annual practice occurred six centuries after after it was written.
With that said, it did talk about fasting which is a good practice to strengthen and discipline self (Proverbs 20:30), and giving to the poor which is commendable (Ibid 19:17).
With that said, I would caution believers not to practice it as it is distinctively a Muslim practice which is in relations to Islamic teachings. God did not give it, and if one were to benefit from the practice, God would not get the credit but Muhammad which, in relations to the bible, a heretic.
First, He does not recognize the exclusivity of Christ as the only way to God (John 14:6), denies the divinity of and the resurrection of Christ (John 1:1-3 & 1 Corinthians 15:1-4). Finally, he claimed to be a prophet of God, claiming to speak for Him which evidentially did not by the false, unbiblical claims he has made (Deuteronomy 18:19-22).
False prophets, throughout history, tried to undermine scripture in order to legitimize their own religion by
1. Claiming that the bible is too hard to interpret, therefore requiring an arbiter, a holy person, an inspired interpreter
2. Claim that the Bible has been corrupted, which therefore requires additions to the Bible to set things straight.
Muhammand used #2 by introducing the Qur'an as according to him, the Bible writers have corrupted the bible to where the truths of Allah have been lost.
Well, there are problems with that claim.
1st - Is God able to preserve His words? If not, then how can they be sure that their own Qur'an, is?
2nd - And if God failed to preserve the Bible, then neither God can be trusted
3rd - And yet the Bible clearly says that it is preserved by Him (Psalms 33:11, Proverbs 22:12, 19-21, & John 10:35).