Last week I had a phone call from one of my colleagues at 12:30am, last night another one texts me at 11:30pm.
It was nothing important, nothing that couldn't have waited until morning. The one that rang me I can't be too mad at, part of the reason he rang was to check that I had got to my hotel okay because I was on my own (they're beginning to realise that if I went missing no-onre would notice for a few days - so they're taking it in turns to check up on me), although he could have called earlier in the evening rather than when I was fast asleep.
I don't silence my phone in case there is an emergency and someone needs to get hold of me, but I'm beginning to think I should.