Timers mS value not corresponding to actual time

Goodday

According to my understanding when using timers the value used is the time in mS.

Timer timerEnrollmentTimeout(10000, timerResetEnrollment);

I have a few timers and they dont correspond the above should be 10s correct? but im getting 17s

Any reason for this or is there a calculation im missing.
thanks in advance as always