On what foot would you give the command "mark time March"?

The command "mark time march" can be given on either foot because the emphasis is not specifically on a designated foot. This flexibility allows soldiers to maintain their posture and readiness regardless of which foot they are on when the command is issued. The command itself pertains more to the timing and rhythm of marching in place than to the specific foot used to initiate the movement.

In practice, when a soldier begins marking time, they understand that they can switch their tempo and maintain discipline without the need for a designated foot. This approach helps maintain uniformity and synchronization within a formation, as each individual can adapt to the moment without being restricted to one foot.