Indeed, in the original bitcoin whitepaper [1], section 3 introduces the notion of "Timestamp server". The <i>primary</i> purpose of a universal ledger (for the purposes of accounting) is to record the correct <i>ordering</i> of events, not their timestamps. This, I believe, is what is meant by the notion of "timestamp" in "timestamp server" in the paper -- it might have been less clear had it been called "event ordering server".<p>[1] <a href="http://www.bitcoin.org/bitcoin.pdf" rel="nofollow">http://www.bitcoin.org/bitcoin.pdf</a>