Differing MD5 when using folder to ISO

[Transic]

 

When making ISO's from the same folder rip of a BDMV, the resulting ISO's always have different MD5's. So for example, if I use the same folder, making no changes, the resulting ISO's always have differing ISO's. Why is this? All the ISO's are of the same physical size and content, so what is changing in them to get different MD5's every time?

 

Thanks!

[LIGHTNING UK!]

The date time stamps in the file system.

[Transic]

Sure enough! I tested it with static dates, same MD5. That explains it, thank you so much.