Case C-306/06: Judgment of the Court (First Chamber) of 3 April 2008 (reference for a preliminary ruling from the Oberlandesgericht Köln, Germany) — 01051 Telecom GmbH v Deutsche Telekom AG (Directive 2000/35/EC — Combating of late payment in commercial transactions — Article 3(1)(c)(ii) — Late payment — Bank transfer — Date on which payment is to be regarded as having been made)