Credor 18K “Big Date” GBLP996Model: Seiko Credor GCLP999 7R87 0AA0 Year: June 2018 Features: The Complication. Whether were talking about mechanical movements or spring drives, the only high end Seiko movement with a Big Date complication is the 7R87 Credor Spring Drive. And this is where the Big Date story ends. For now, at least. Over the past fifteen years, Seiko has released just a handful of Big Date Spring Drive models, spread thinly across 2009, 2014, 2018, and 2019. The