Is there an official or at least an up to date web blockchain explorer for Zeitcoin ?
There should be one soon. I'm waiting for it as well to get some projects underway. The devs stated that it should be available in under 48 hours after March 14th. Therefore, it should be available no later than March 16th.
I'm waiting for it too. It won't be possible to do serious real life business without an official blockchain explorer, and ZeitCoin worth nothing without serious real life business.