As long as it was a sealed container, I would say it's OK. Diesel lasts forever. It's a lot heavier and tougher than petrol so it doesn't evaporate in the same way.
I'd also argue that petrol is a lot less volatile than people make out. My Dolly Sprint has been in the garage for the last 2 years and has never been out on the road in that time. Nonetheless it still starts first time, every time on the ancient fuel in the tank.
We have diesel in a tank for a standby generator at work that is over 40 years old. The engine will stand for a few years at a time and start first swing
We have diesel in a tank for a standby generator at work that is over 40 years old. The engine will stand for a few years at a time and start first swing
Excellent.
So I don't need to buy a diesel car for another 33 years!