Thanks to redditor @takealookatwrist for informing me about the CDT mod for my recently resurrected W800h! Mod enabled and I put in a yellow filter gel to boot. : r/casio
Casio W800H] With countdown timer mod : r/Watches
Casio W800H Countdown Timer Mod - YouTube
A bargain story (Casio non-G W800H) | WatchUSeek Watch Forums
Let's Hear it for the Casio W-800H! | Page 2 | WatchUSeek Watch Forums
18240 Casio EU Watches mod. W-800h-1bves for sale online | eBay
Modifying a Casio F-Series Digital Watch – Shell Zine