Which foot is appropriate for giving the command "Mark time march"?

The command "Mark time march" allows for execution regardless of which foot is forward. This flexibility means that soldiers can start marking time on either foot without any impact on the command's execution or the unit's overall performance. The intention behind allowing either foot is to accommodate different formations and individual preferences, as well as to make the transition smoother depending on the preceding instructions or movements.

In marching drills, providing the option of either foot helps maintain a consistent cadence and ensures that soldiers can easily adapt their movements without disruption. Therefore, "on either foot" is the most appropriate choice for executing the command effectively.