I’m sorry, 6 to 8 months for mustard (still a short time in my opinion), ketchup is 1 month unrefrigerated, longer in the fridge (I’ve had mine for quite a while, tastes fine).
I regularly keep Ketchup unopened in the pantry for 6-12 months before opening it and it is just fine. then after that it can sit in the fridge for at least 6 months more. Once it ferments, it’s bad. I can easily tell the difference.
sniff, sniff... the milk in the fridge is about to go bad.... and there it goes </Bobby Hill>