The doorbell cut like a starter pistol through our Friday morning lie-in. My wife looked up from her novel and I sneaked a glance across at her from beyond the sports pages, our silent stares issuing the identical message: ‘Well, are you going or do I have to?’ My resolve not to be first to blink dissolved as she played her trump card: ‘You’ve not gone and booked a client in, have you?’ Once sowed, that insidious seed of doubt was sufficient to propel me from bed, into dressing gown and downstairs, stopping off en route for a rapid check of my trusty diary. Just as I thought, a joint day off, no mistake.

Opening the front door, I was confronted by my newish client, who, on seeing his therapist clad in dressing gown, and barefoot, remarked: ‘Oh! You weren’t expecting me? Have I got the wrong day?’ I duly produced the diary evidence: his next appointment not till Monday. He wandered off, mumbling apologies, and I went back upstairs, clutching my precious diary and gave it an affectionate pat.

Twice in 30 years my reliance on my diary has been my undoing. On each occasion I’d given the client an appointment card but omitted to write down my side of the bargain. The first was one of my earliest Marriage Guidance clients; he was creepy and I was frightened of him. The second occasion, a decade later, occurred 10 sessions into what turned out to be my longest and most personally exacting case; a hugely depressed and suicidal woman, the last client on earth I would ever want to let down. These days I take better care of myself, see more supervisees than clients and always allow a minimum half-hour between appointments, no more than four a day, usually fewer. Over the years my diary has shrunk from A4 to A5, a working life, there at a glance, week-to-view. The names change but the pattern remains the same. My blessed diary, I’d be lost without it. Accompanying me into each session like a faithful sheepdog, it sits at my side, the physical embodiment of the therapeutic alliance, symbolising both the promise and limitations of my commitment.

One summer holiday on a small Greek island, the local mayor, and owner of the small fish restaurant where we ate most nights, offered to lend me his rowing boat and rod, to fish the bay the following day. ‘What time, and where shall I meet you?’ I asked. ‘Ahvrio (tomorrow),’ he replied, ‘I find you.’

I was agitated all morning, constantly looking around, pointlessly checking my watch. He found me. It was a one-village island of less than 200 inhabitants; only tourists wore watches. However, home and work is not a quiet corner of the Dodecanese, but West Yorkshire, and my diary contains fine measurements rather than impressionistic estimates, and the sessions it announces start and end at prescribed times. So too does my working day. My wife recognises the signals only too well. Her car journey to work enables her to slide gradually into her professional self. But working from home I have no such device, and before she leaves the house, she feels the keen edge of my withdrawal into myself, way beyond her reach. It’s not easy living with a therapist, especially one who works from home.

By appointment, ideally the same time every week; your slot, count on it, attachment theory incarnate. Of course, for some clients, the pattern is remarkable for its built-in unreliability and inconvenience. ‘How come, the one day I desperately needed to see you, was smack in the middle of the week between appointments?’ asked one frustrated and emotionally bunged-up client, who never let me within a mile of her vulnerability. It was a good question.

I suppose weekly appointments, in allowing more separateness than togetherness, discourage dependency, or if you prefer, encourage autonomy. Yet the inherently disciplined nurture feels more like Truby King than Benjamin Spock, despite the person-centred principles we might hold dear. We could, of course, do away with appointments altogether and just hang a ‘Drop In: 10–4’ sign upon the gatepost. Or perhaps we could take a leaf from Dr Paul Weston in the TV series In Treatment, who gives certain more vulnerable clients his mobile number, saying, ‘Call me, anytime.’ I gasped. It expressed the extent of his care, indeed his love, seemingly stretching way beyond my own. But limits are loving too, the limits of a diary that says, ‘This is when I’ll be here for you, and I shall never promise more than I can reasonably deliver, so as not to let you down.’

Kevin Chandler is a therapist and supervisor in private practice, and author of Listening In: a novel of therapy and real life.