Shri Subbudu,
For something to be called a reality should be experienced in the same way by everyone everytime. If time were a reality the duration or passage of time should not alter. Since it has to do only with the person experiencing is not due to the nature of the time, it is only a perception. Time is totally a mental construct and is related to mind in the way space is related to body.
How do you know the duration or passage of time alters?
Since it has to do only with the person experiencing is not due to the nature of the time, it is only a perception.
If you want to interpret it that way everything is perception. But matter exists. It is not because of your perception that it came up. To give you an example. Suppose I and Nara secretly plan and let loose a dog in your bedroom, it is not perception. It is real. You see the dog and then your mind adapts to this material information. Now I and Nara ask the dog secretly to move next to you and sit beside you. Again your mind has reacted to it. Then the dog leaves the room and you are relieved.
First, the dog made an appearance unexpected. That is not just a perception. We knew it and you also saw it.
Second, dog comes close to you unexpected. That is not just a perception. We knew it and you also saw it.
Third, dog leaves room. That was not expected. That is not just a perception. We knew it and you also saw it.
In the meantime you saw the wall clock. The clock hands have moved from the first event to third event. That is not just your perception. We knew it and you saw it.
In the meantime your heart has beat 1000 times. That is not just a perception. You knew it something happened to your bp and something else happened. After first event some sweat started coming. We saw it also. The dog left the room and sweat stopped. We saw it.
As you can see matter is related to body, but not only your body everybody can perceive change to it if they are there when the event occurs. The transformation between the two events is called time. You can use a clock , you can use the sun to measure its change. But yes when the dog came, you were so scared. One hour seemed like one day. But the clock small leg moved only by one number. Suppose someone came to your room just before the dog came and made note of the clock and left. Then after one hour after the dog had left they saw the clock again. It had moved by one measure. They neither saw the dog come nor leave. Let us make it even more complex. Let us say the person who saw the clock first was different from the person who saw clock last. Both did not know what each had in mind. Still the facts are that the clock had moved only by one measure.
Now you will have a theory that since everybody is the same brahman a unified perception (based on advaita) has led to such imagination of clock motion. Isnt it just a theory? How you can expect this theory itself to be used as an argument to support advaita?
What I have heard is that depending on frame of reference , the length of interval between events change. This is the relativity principle. However no matter which frame of reference you are , event 2 does not happen before event 1. If that happens then we can say time is a perception. Similarly if event 1 and event 2 cannot simultaneously happen. This would happen if it is a perception.
So using such logic is injustice to Advaita.
Advaita probably says time is because of perception. But this cannot be proven this way. Time is a perception only if change in matter itself is just a perception. Change in matter is only a perception if you can prove that no snake is a snake but only a rope. That is left to experience. To some it is always a snake. To some it is always a rope. How do you decide who is correct. If the rope can move by itself , crawl on the floor , without your intervention ?