Autocontrol / metering urinals - 12sec or optional?

Dear all, when calculating proposed case water consumption budget for public autocontrol / metering urinals…is there the same requirement like the 12sec requirement for public autocontrol / metering lavatory faucets? I assume there is no such requirement so we can specify any length of flushing on the project. Is that a good assumption? When considering urinals there is probably nothing like standard hand washing process like when using lavatory, isn’t there? We ended up with setting reasonable length of flush that should be o.k. for effective water-cleaning of urinals. Thanks for any kind of help.