The Gazette reported last week that executive law firm members of environmental group the Legal Sector Alliance all pledged to participate in an ‘Earth hour’ event last weekend, switching off their lights for an hour from 8.30pm on Saturday 27 March. Firms involved include magic circle players Allen & Overy; Freshfields Bruckhaus Deringer; Linklaters and Slaughter and May, as well as City firms Herbert Smith; Lovells; SJ Berwin and others. But hang on a minute – at 8.30 in the evening on a Saturday, some of those poor corporate lawyers are just finishing off the office takeaway pizza to get down to some heavy duty due diligence and document drafting. Obiter is bound to wonder, did the billable hours clock really stop ticking? Or did the local Tesco Express mysteriously run out of candles on that day?