24º is only a number. It's used for static timing.
If you used a piezo electric dynamic/timing light system, the correct number is 11º or 15º or some such, BUT NOT 24º. Brian Carlton may know the correct number.
If you used an electric RIV method, again the setting is NOT 24º, but when the lights do their on/off thing. Brian again:
Specialized Indicator for IP Timing
Edit: Beat by BHD by a minute. rats!!