QoS Shaping token refresh rate

[BVC]

Just trying to understand when the token refresh occurs for the QoS shaping mechanism. From my understanding tokens are put into the Bc token bucket (single-rate three colour bucket) at the Tc rate? Is this correct? Or are tokens put into the bucket are the start of each second?

[Joseph W. Doherty]

I believe tokens are added each Tc interval, or put another way, token bucket is refilled each Tc interval start.

BTW, reason for question?  Are you seeing, what you consider, unexpected shaper behavior?

[BVC]

Thanks for confirming.

Only asking due to brushing up on QoS for an exam, just wanted to confirm this info as Cisco guides and cert books are not very specific on when the actual token refresh interval is.