I know of at least two FIDE approved clocks, the DGT 2010 and DGT XL, that only show seconds when the clock is under twenty minutes. The FIDE “Standards of Chess Equipment” says “5.4.3.2. The display at all times should show the time available to complete a player’s next move (preferable to display seconds also from beginning).”
Translation: “The display at all times should show the time available to complete a player’s next move. We would prefer that the display also includes seconds at all times, even when the time remaining is over 20 minutes or over 1 hour, but we may begrudgingly approve a clock that displays seconds only when the time falls below these numbers.”
This still leaves open the question of whether USA-style delay meets the “at all times should show the time available to complete a player’s next move” requirement. IF the clock always shows delay time as countdown digit(s), AND it also always shows main time in some form – and that’s a big IF and a moderately large AND – does this meet the requirements? After all, “the time available” is just the main time plus the delay time, and both are displayed at all times, right? Or is this a stretch too far?
Throw in other monkey wrenches – such as a clock that shows only the delay (and not the main time) during the delay, or flashes between delay and main during the delay, or shows the delay only as a flashing colon or something – and all of a sudden you have questions FIDE apparently doesn’t want to deal with. My guess is that FIDE really wants delay to just go away, and be replaced with increment all around the world.
My own preference is that all clock manufacturers begin to accept the idea of displaying main time (h:mm:ss), delay seconds (dd), and move count (nnn) fully at all times, even if this requires a wider display area, or a two-line format with h:mm:ss on the top line, and dd and nnn on the second line in slightly smaller digits.
Bill Smythe
From what I was told by FIDE, they (at least currently) don’t care about delay when certifying clocks.