Your reset date is the same as your billing renewal date. If you signed up on the 14th of the month, your subscription minutes refill on the 14th of every following month. For yearly plans, the full annual allocation lands on the renewal date. You can see your exact reset date on your plan page.

For monthly plans they expire on your reset date. There's no rollover and no carry-forward. If you didn't use everything, the unused minutes are gone, and the new cycle starts fresh with the full allocation. For active annual plans, any remaining credits roll over seamlessly into the next cycle. However, if the annual plan is canceled, these credits will expire at the end of the subscription period.