Over the last ten years it has gone from no overtime to "Can you do a wee bit of overtime?", then "You are working this weekend" to not even asking me and just expecting me to be in the office working late.
It came to a head last August when I was at a big-4 consultancy. The usual email about ordering dinner went around, that was code for we are all working late tonight. I said "Sorry, I don't need any I'm off home". Within a minute the project manager was at my desk saying "Well, we clearly have a problem and you need to fix it now." They were always so careful to not actually say the word overtime, it was all code such as asking us what we wanted for dinner or telling us that the security man would be locking up late and the like.
That was the point when I knew that I had to change things.
The worst thing was that I had told that company I could not work late as my wife worked evenings and we have kids. I got a note added to my contract acknowledging this, but they wouldn't honour it. They even went as far as suggesting that I hire a babysitter or ask my wife to give up her clients. They were oblivious to the fact that I would rather be with my children than earning €100k.
I should have done it sooner. About five years ago I was a company that claimed to be family friendly, but was anything but. During my annual review I was marked down for not "Giving Time to the Company" basically not doing overtime. I said that expecting me to give away my skills for free was unprofessional. I was told that I was unprofessional for even thinking that. That is when I should have taken the plunge to go it alone, but I held out hoping for a better employer.