For me, this manifests in the migraine starting to build from Friday early afternoon and reaching the effective treatment window by about 10pm-midnight. Sadly by that time I'm usually already knocked out by one of the preventative meds I take making me unable to take meds for the migraine until that window has passed and the pain is so great that it wakes me (trust me, being woken by your brain feeling like it's exploding inside your skull is a really horrific way to wake up).
The irony of not being able to take my attack meds in the right window because of my preventative meds is not lost on me. As a result I end up losing my whole weekend to migraine.
The Migraine Trust have a factsheet about Migraine Triggers which goes some way to explaining the weekend migraine phenomenon.
The crux of it for my own weekend migraines I believe, is my body's way of managing to push through the things it needs to. This has proved to be the case when I've handled way more than I normally could and still been unscathed by migraine until after it's over, both fun things like geeky conferences or my wedding and not fun things like work.
So essentially I manage to push myself through my week at work, and then as soon as it's over I'm hit with a migraine. By the time I then go back to work, in a haze of Migraine Hangover, I haven't had the break I should have had and I find myself again, pushing through the week at work, to be hit my migraine as soon as it's over.
You can see the cycle here.
This weekend it's my husband's birthday and I really don't want to ruin it by being out for the count with migraine yet again! The solution I've come up with, which I desperately hope works, is to take Friday afternoon as a flexitime half day off. I'm hoping this will kick my body out of the routine and either, ideally, not trigger a migraine as a result, or, more likely, trigger the migraine earlier and allow me a chance to treat it in time to abort it and allow me to be reasonably fit for the weekend.
Wish me luck! Oh, and wish my husband a happy birthday with a migraine-free wife!
I'd be interested to hear from other migraineurs in the comments if you also suffer from the curse of Weekend Migraine.