I don't want to jinx myself, but I've been called twice in my 35 years. The first time I was barely 20 years old. My boss at the time wrote a note stating I would not get paid, and I lived on my own and was going to school. So I got a hardship on that one.
The second one was about 6 years ago and I had to go. They were calling the last group of the day and of course they called my name.
It was so late in the day that we had to come back the next day. Luckily I got out of it. The defense attorney dismissed me.

Good luck, I hope you get the postponement.