After arriving in the Schengen zone from the UK, you want to wait until after midnight to have your passport stamped. The extra day of unspent leave will allow you follow through with other reservations you have made.
Yes, this is possible if another Schengen arrival flight is arriving closer to midnight. In other words, you cannot just show up at the immigration desk in a deserted terminal. You need to clear immigration in a 'cluster' of people who have arrived.
As for the air side waiting time, appropriate dress and grooming is essential. Remember that the Grenzpolizei have the right to challenge anyone near a border, even if the person is waiting.
Your strategy is mildly abusive, but it's legal and will certainly work if a few caveats are observed.