When making homemade dilly beans the dilly beans need to sit in the jar for at least 6 weeks for the flavor to fully develop.
You can open the jar of dilly beans before 6 weeks and eat them sooner but to get the best flavor of the dilly beans you should wait for at least 6 weeks.
I've eaten dilly beans that only sat in the jar for a few weeks and the taste was not as good.
Now I wait at least 6 weeks and make huge batches of dilly beans in advance so I always have several jars of ready to eat dilly beans.
Waiting 6 weeks before opening up a jar of dilly beans allows the flavor to set into the dilly beans as the dilly beans will have more time to absorb the flavor and juices.
The longer the dilly beans sit the better off the flavor will be.