What is time? What exactly is time?

The definition of time is the process of the operation of mental dharmas and material form; the dharma used to display the length of this process is called time. In other words, the length of the process of material change is called time. For example, when a baby is born, one month is called the full month; one month is time. Being born and growing for one year is called one full year of age; one year is also time. In fact, these are all just one stage of the baby's growth and development; in essence, there is no such thing as time. Whether it is one second, one minute, one hour, or one day after a baby is born, or one year, ten years, or twenty years of growth and development, it all refers to the process of growth of the baby's physical body. There is no dharma called time; time is passively displayed.

This is defining time in terms of material form. If time were defined in terms of mental dharmas, then age stages would be divided according to the degree of a person's mental maturity: those with lower cognitive ability would be called the infant-toddler period, the childhood period, and the youth period, while those with mature minds and high cognitive ability would be called the adulthood period, the middle-age period, the old-age period, and so on—there are many such names.

The speed and length of time are demarcated according to whether the mind is concentrated or not, whether the emotions are stable or not, and whether one is leisurely or hurried. The more concentrated, stable, leisurely, comfortable, and joyful the mind is, the less time one perceives; conversely, the longer the time one perceives. Some people say that time now seems to have stopped and is no longer moving; in fact, it is the mind that has stopped moving and no longer discriminates external objects, so the time displayed by external objects naturally cannot be perceived. In fact, there is no such thing as time; to speak of time as moving or not moving is all conceptual proliferation (prapañca), just like discussing how a tortoise's hair or a rabbit's horns might be—it is all conceptual proliferation.

 When we look at time, we look at clocks and watches; on a clock, the second hand, minute hand, and hour hand combined together display time. Without these hands there is no time, and with these hands there is likewise no time. Most fundamentally, time is displayed according to the position of the sun's movement across the sky; without the sun there is no time, and with the sun there is likewise no time. When the sun rises above the horizon, humans define this state as the morning of a day; at the same time the temperature is relatively low, so the state of the morning sun arising is defined as morning. When the sun rises to the sky overhead, humans define it as the noon of a day. When the sun descends below the horizon, humans define it as the evening of a day. Thus one full circuit of the sun's movement is defined by humans as one day of time. Then, by tallying the number of the sun's cycles, they are respectively defined as ten days, half a month, one to twelve months, one year, two years, and so on. All lengths of time can only be displayed by relying on material form; there is no real dharma called time.