Possible?

I`m having hard time figuring out how to log both timestamp and MAC address of Trial-Hotspot users.
On one hand I have Mikrotik router, on other, 3.6 Dude glued on Windows Server 2012.

Now, what I wish to perform is as following; log each Hotspot user`s MAC address and timestamp of when user hooked onto the WiFi and when he disconnected.
This is required as in EU; logs must be kept for some time (one year, five years), with legalities in sight.

Is this even possible and if so, how?
I just need some guidelines; so if anyone helps me out I`ll do 20 Hail Mary`s and 20 pushups in his/her name:)


Many thanks in advance;