When to give up on non germinating seeds?

I bought some Skunk #1 from seedsman and the first 10 pack had only one that popped a tap root but never sprouted from the jiffy pot. I emailed seedsman with my problem and he sent me another 10 pack of Skunk #1. These have the same problem it looks like. I soaked them and nothing. Put them in paper towels and nothing. Some may crack but never express their roots. What is the longest time you guys have seen for seeds to germinate. I can sprout bag seeds no problem so I am not a total idiot but I do need help.

I have given seeds 7-10 days before i've given up on them completely. i've seen em sprout after 5 or 6 days. usually 2-4 for me.