Can anyone define time without using a reference to time?

I prefer John Wheelers definition,

Time is natures way of ensuring everything does not happen together.

Change?

The observable difference in measure of a system devised by an
entity to record the number of units between two points of motion
made by an object or otherwise observable phenomena?

:D

Change in entropy is usually used to give the direction of time.
As for the actual measurements then you need to have other objects to compare it to.
eg if the universe had only one electron in it how could you judge/measure the time difference ( or the inertia ,for that matter!)
The wheeler theory is probably the best attempt at this time...

Time is space, just like matter is energy.

and i imagine that there is a quanta of time, as in string/m-theory, where space/time is composed of interlocking/knotted strings...