968 / | HD | HOROLOGY |
564 | DD | INDICATING THE TIME OPTICALLY BY ELECTRIC MEANS (subclass 577 takes precedence; by mechanical means subclasses 139 and 162) [G04C 17/00] precedence; by mechanical means subclasses 139 and 162) [G04C 17/00] {6} |
573 | DD | .~ By drums or drumlike devices [G04C 17/00T] {1} |
574 | .~.~ With date indication [G04C 17/00T2] |