Given that all laws of physics (except the Born rule) are expressed as partial differential equations in time evolution. This makes their functioning time symmetric as all the limits used are not one-sided limits.
My question is how does one make sense of the $2$'nd law of thermodynamics?
The second law states: "the entropy of an isolated system will always increase"
Like what I find it amazing one can take time symmetric tools and suddenly create a time asymmetric tool (in the sense I can use the second law to tell that $t_2 > t_1$ where the entropy at $t_2$ has increased? Am I wrong and there is some subtle hidden time asymmetric tool used as well?