Temporal constraints

<div class="demo"><div class="head"><b>WITHOUT OVERLAPS</b><span>room A</span></div><div class="stage timeline"><div class="axis"><div class="bar old">existing 10–12</div><div class="bar new" id="booking">11–13</div></div></div><div class="foot"><span id="bookstatus">overlap: rejected</span><span>time range</span></div></div>

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let n=0;function tick(){let e=document.getElementById('booking');e.classList.toggle('ok',!!n);e.textContent=n?'12–14':'11–13';document.getElementById('bookstatus').textContent=n?'adjacent: accepted':'overlap: rejected';n=1-n}tick();const t=setInterval(tick,1250);document.querySelector('.demo').onclick=()=>{clearInterval(t);tick()}