I understand time as a aspect or feature of energy, as the duration or measure of the motion of energy devoid of any direction. There is no arrow of time but our minds merely perceive time as one-directional. Energy in motion or in vibration causes progression and regression, growth and decomposition and we perceive this as the passage of time. Time is a duration or measure but it is energy and matter that does move in a direction. Time comes from energy which is eternal, not having been created nor to be destroyed, thus time itself has been and is eternal.