Why is it, when you need to call the vet out it's always at 10:30pm on a bank holiday weekend?!

Noah my Shire is approx. 20 yrs young and has a really bad arhythmia (Spelling?) in his heart.  Anyway, I brought him in for a little hack on Saturday morning but as I was grooming him I noticed him shivering so instead I rugged him up and put him in a nice cosy barn with tons of haylage.  Anyway, when I went over in the evening, he was still on the chilly side and hadn't eaten much and there was only wet to muck out.  The lack of droppings during the day isn't unusual for him so I thought I'd see how he was doing later.  However, when I went over to do the late night check there were still no droppings, the haylage had only been nibbled and he was obviously in some discomfort so I called the vet.

The vet said it didn't look good as it could be peritonitis and even if it wasn't we could see his pulse shooting up his neck and his temperature had risen by 3 degrees, but most worryingly his heart rate (such as it is) was over 70.  The vet was expecting his heart to give out over night but gave him a painkiller and some antibiotics and told me to see if there were droppings in the morning.

There were droppings  but he was still pretty sick.  Anyway, he's gradually picked up and is raring to get out to the field again.  His sheath has become quite swollen but someone told me that's quite common when a gelding's been ill-something to do with the toxins being stored there.  I'm gonna ring the vet about that this morning.

Anyway, sorry for the long post, just been so worried I wanted to get it all off my chest!  However, it looks like Noah's not ready to leave us yet, thank God!  He's such an angel, I don't know what I'd do if I lost him.