Credor “Big Date” GCLP999Model: Seiko Credor GCLP999 7R87 0AA0 Year: April 2009 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 even more surprisingly, there are only a handful of models that even use that movement and theyre all discontinued. The Design. The dial was recently described to me as resembling the lines you might find in