If I am in an instant of time t1 and in a subsequent instant t2 an event x occurs, at the moment t2 I can state that at t1 the event x was determined. This would be false only if it were possible to change the past, but changing the past does not mean that the event did not happen, but that it did happen and then it was changed. So, if x happened and nothing can change this fact, x could only have happened.
Let us try to understand how one understands the time and its relation to environs-
There are two main concepts about time recognized as firstly, physical time that is objective and secondly, psychological time that is subjective and has a mind-dependent existence.
In Theravada Buddhist philosophy, the idea that time does not exist independently is quite significant.
Although many Western thinkers (such as Plato, Aristotle, and Kant and scientists such as Sir Isaac Newton and Albert Einstein) were interested in investigating the concept of time, only some of them agree with the idea that time existence depends on the mind.
Henri Bergson, a renowned French philosopher, is one among a few who supported the idea that time is mind-dependent since he suggested that real time, which he called “duration”, exists merely in our consciousness. In this study, the researcher has critically examined Buddhist and Henri Bergson's concepts of time and sought to identify their similarities and their distinctiveness.
It is because of what time is that we can succeed in assigning time numbers in this manner.
Another feature of time is that we can place all events in a single reference frame into a linear sequence one after the other according to their times of occurrence; for any two instants, they are either simultaneous or one happens before the other but not vice versa.
A third feature is that we can succeed in coherently specifying with real numbers how long an event lasts; this is the duration between the event's beginning instant and its ending instant. These are three key features of time, but they do not quite tell us what time actually is.
Even its hard to 'determine' that actually an event occurred at time t1 if the signature of the event is not available to be observed at the later time.
When the mind along with consciousness is involved in the measurement of flowing time -one can only state about certain probability of the event may have happened at time t1.
The concept of 'measurement' drives into the picture as we start looking at the clock and putting down numbers for t1 and t2 signifying those events.
There are two main concepts about time that are distinctively recognized by philosophers and scientists which are firstly, physical time that is objective and exists outside of the human mind and is a part of the natural world and secondly, psychological time that is subjective and has a mind-dependent existence (Dowden, 2012, Weinert, 2013, pp. 7–84).
For Plato, time was related to regular physical events such as the motion of celestial bodies which are ideal instruments to measure time since their orbital periods are regular and eternal and therefore, can be used to identify human time such as the duration of one day (sunrise to sunset) and the duration of a month (lunar cycle) (Weinert, 2013, p. 9). Aristotle who was the first Greek philosopher to support the idea of subjective time since he suggested that there is no time without a soul (Aristotle, chap. 14). Similarly for Kant, time and the thought that perceived it cannot be separated (Ricard & Thuan, 2001, p. 138) which implies that time is mind-dependent and subjective.