The dark art of school timetabling remains a mystery to all who have not actually written one - an arcane pursuit at the best of times, never mind when a pandemic has been thrown into the mix.

It is a pursuit that deploys language indecipherable to mere mortals: blocks, triples, bands, carousels, disjoints, fit points, homogeneous and heterogeneous options, schematics and principles of compatibility. It is the preserve of the depute (normally, although in a number of cases, the principal teacher of maths or, God forbid, the headteacher), who will lock their door from March through to April, and post a scary notice to ward off unwary staff and pupils.

When they emerge with a workable formula for release to the staff body in the middle of May, the only thing for certain is that nobody will be happy. The best they can hope for is that their colleagues will still talk to them. In a worst-case scenario, it may be that the teacher with a light Monday and Tuesday who is then full-on from period 1 Wednesday until the end of the week will only forgive them when they have the opportunity to make amends the following year.

Those who have dealt with such issues know that the first thing is to be sure you get your staffing allocations right. There will be those who want to retire, of course - and you should know about these well in advance - but there will be others who want to either increase or decrease their hours. Flexible working is a right for all your staff and you need to make sure they are well accommodated. In particular, you need to look out for those who wish to work part-time. You will have to respect their wishes but not necessarily guarantee them. Many will have sound reasons for needing certain days off, including childcare issues that have been arranged far in advance and may not be moveable.

Principal teachers and other staff may have less sympathy towards part-time staff than they should when it comes to timetabling. While, legally, it may be theoretically possible to give a 0.2 full-time teacher one period a day from Monday to Friday, this would not be deemed good practice and could constitute a reasonable case for constructive dismissal. However, it is also difficult to explain to a department that sees S1 pupils twice in the same day for maths that the reason why is that one of your teachers in another subject wants to have Thursday afternoon off. Nobody else ever knows about conundrums such as these; one small timetabling problem can often have a disproportionate effect on everything else going on in the school.

In a small school, for instance, you may have two teachers in one department working for three days and four days respectively; assuming you will need somebody in attendance throughout the week, there may be only two days when both members of staff are in the school. If the subject is taught in all years through the broad general education (BGE) and has qualification classes, then timetabling becomes a nightmare and the rest of the school may be held ransom to the demands of these particular teachers.

As chief timetabler, it is your job to address such headaches and keep all your staff happy. It would be a rare school indeed where part-time staff were not among the most valuable and committed of your teachers. They often put in hours far beyond their contractual time and maintain their enthusiasm by spending the week doing other things away from school. Often, it is politic to cede to their demands and cope with the impact it has on everything else.

School timetables: Stretching to do the splits

One of the most exacting knock-on effects is split classes - and this is especially pronounced in small schools with limited staff but not limited subjects. Split classes come in a variety of forms. Science classes with three periods per year in the BGE may have a 2:1 split between teachers or, in extreme cases, a 1:1:1. Practical classes could be looking at a 1:1 across the week and, in the senior phase, there will be Highers with 3:3, 4:2 or even 5:1 (and you thought football managers’ tactics had got convoluted).

Some of these splits will be easier to manage than others and can lead to quite innovative solutions. Maths classes in S1 with five periods per week can look to a different teacher for one or two periods to concentrate on numeracy. English classes could work similarly with a separate class for grammar. And, as a principal teacher assigning staff to qualification classes, I always found it useful to give two periods per week to our NQTs and have them concentrate on some specific part of the geography course - urban development, say, rather than the more specialist soil profiles - and then watch them flourish with the increased responsibility that was not given to their peers in other schools.

But these are the nicer aspects of the split class. In other cases, it can cause problems that last the whole year. Teachers in the BGE working through a set curriculum can find it frustrating to have to constantly liaise with colleagues about what they will be teaching in their one period per week. And if they don’t manage to complete the lesson they have planned, does it continue with a different teacher the next period or does it wait until the following week (by which time pupils will obviously have forgotten what they were doing)?

It is important to know in advance which subjects - and which teachers - lend themselves more to split classes and which will pass on no end of problems to you as the year goes on.

There is a lesson, here, in communication that all senior management teams need to be aware of: you should be finding out about departmental demands as early as possible and pestering principal teachers until you get them. For instance, home economics will not be happy if they don’t get double periods (and two periods spread around a morning break does not count). Maths won’t be very chuffed with double third years first thing on a Monday morning (then again, who would?).

At many different stages in the process, principal teachers will have to be consulted to make sure things are going well and, very importantly, that you have avoided stupid mistakes. A timetable can fall apart through the simple error of allocating four periods to an art class in S2 and only three to English.

Principal teachers can be strong allies in the process, but some do have a tendency to secrecy, which leads to different problems. It is important to ensure that the timetable release to their own staff is synchronised across the school. Some will allocate classes with no consultation (some maybe even ensuring that they teach just small classes of seniors), while others will have much fuller discussions. The most important thing to avoid is some staff having access to the full timetable while others do not. This can lead to a lot of ill feeling.

Even when everything is public knowledge, there is always the tendency for some staff to tot up their non-contacts to compare with everyone else in the school, conveniently forgetting that they may well have been the beneficiary of such perceived unfairness for the previous two years.

Algorithms miss a beat

There will be friends within the staff body who may help with the timetabling task. There may also be complex computer software available.

Some such systems are excellent at making sure all classes and all subjects are allocated across the week, but there is a need for a human touch - computers, for instance, do not realise that five S1 classes in maths allocated to the last period every day is a bad idea. And there will be friends within senior management teams with the flexibility to fill in some impossible gaps.

Do think carefully here, however. Nobody in S2 who sat through a year of me teaching religious and moral education came off better for the experience.

Finally, when it’s all done and dusted (or so you think), prepare for the aftermath. There will be the senior pupils who want to change their subjects and can’t remember what they chose in the first place. There will be the irate parents unhappy that the combination of English, art, history, physics, PE and practical cookery - or myriad other eclectic combinations - is impossible to timetable. And there will also be the staff who use the “ridiculous” combination of classes you have given them as an excuse for the poor behaviour of their pupils.

But, if it all seems too much, I have one final, essential tip: find somebody else to do the bloody thing for you.

John Rutter is headteacher of Inverness High School

This article originally appeared in the 19 February 2021 issue under the headline “Timetabling for beginners”