I’m a geek, I admit that, but it does help sometimes. As I’ve been writing the serial novel (set over about 15 years) I’ve had a list of every month covered by the novel, and I’ve written down major events next to the relevant month. I worked out birth dates for my two main characters and wrote their birthdays in, and I even checked (very easy on a computer) what day of the week they fell on, in case that seemed important. It’s helped me get a few events straightened out, and I’ve avoided (for the most part at least) mentioning world events that haven’t happened yet (though I’m keeping references to the outside world to a minimum, following my own advice for a change) or writing about the wrong season.
Not everyone is as pedantic as me, nor would I want them to be, and in some instances it doesn’t matter too much – I noticed that in the first few lines of Philip K Dick’s short story Imposter a wood burned down ‘a few weeks ago’ whereas the reason for the fire (as you realise later) happened about 8 days ago, but it didn’t bother me as it was a brief and well-paced story where plot was everything. One place this kind of mistake has bothered me recently is in one of my favourite detective series – I’m not going to say which because I don’t want to put anyone off the series, which in general is very good.
I appreciate that writing any long-running series is difficult, particularly the kind where each novel has a contemporary setting, but the novels might be written over 30 years or more. If your detective was middle-aged to start with, you either stick to the chronology and take him to retirement (which some authors have done) or you deliberately make it vague – girlfriends and cars come and go but age is never mentioned, and he’s apparently been in the same job since England won the World Cup.
The series in question does allow change, albeit very slowly, so for quite a few books one character is described as recently retired and finding it hard to adjust. In one particular book he asks a long-standing female friend to marry him, and in a later one (the one I’ve just read) he refers back to that as having happened a few years ago, BUT in this same book he also states that he’s been retired for less than a month. Why pin the time down? Not only does it mean we have to believe all his recent adventures have taken place within a month, but it makes it so easy for him to directly contradict himself, as with the remembered marriage proposal.
I finished reading the book, but it wasn’t as satisfactory as all the previous ones I’d read. Once I’d had such a contradiction flagged, I started noticing (and worse, resenting) all the minor violations that crop up all the time in lots of stories – someone’s already sat down at the end of the paragraph, then they sit down, or a tool that’s been dropped is right where it’s needed a sentence later. It’s reassured me that I’m doing the right thing working out a timeline when I’m setting a story over a long time, I just hope it doesn’t put me off serial detection.