I wasn't going to answer, because there is no answer, but, anyways...
First: common practice is...
Common practice is to frequently measure the property you are after, as well as others, such as internal energy, density and make a plot. The property will fluctuate but eventually reach an equilibrium that is easy for the eye to spot on a plot. Or, use the maths as Chodera has done paper here, open access, thanks BioRxiv, and let the computer tell you when you have reached equilibrium.
This is what is done. either manually or algorithmically check that the property is fluctuating about some mean value with a standard deviation you would consider indicative of equilibrium.
This, however, doesn't tell you how long it will take, it only tells you how long it took.
Second:...
The idea I propose, which is crude, possibly too crude, is a rather simple one...
If you know what something value is, and you know its rate of change, and you know where you want it to be, you can figure out how long it will take. The problem is really knowing the rate of change. If we take a first order expansion of pressure as a (made up) function of time we could say we have
\begin{equation}
P_{\rm equilibrium}(t) = P_{\rm current}(t_{curr}) + \left(\frac{\partial P}{\partial t}\right)_{t_{curr}} \Delta t
\end{equation}
It would be simple in theory to estimate the rate of change of pressure by measuring the pressure at two different time steps
\begin{equation}
\left(\frac{\partial P}{\partial t}\right)_{t_{curr}} \approx \frac{P_2 - P_1}{t_2 -t_1}
\end{equation}
So you could rearrange for the time
\begin{equation}
\Delta t = \frac{P_{equil} - P_{curr}}{\frac{P_2 - P_1}{t_2 -t_1}}
\end{equation}
You could probably replace P for pressure with P for property.
Unfortunately this probably won't work, particularly in the case of pressure, since instantaneous pressure can jump wildly. You would need to calculate the rate of change many times and take the average.
Another reason it likely wouldn't be that accurate would be that the rate of change would probably not be constant. It would be like when a download says 5 minutes remaining, and then in 1 minute it says 10 minutes remaining, and then in another minute, 30 minutes remaining, and then in another minute Download Complete.
Anyways, that is a thought I had.
In the event you were doing an NPT and wanted to guess what the volume would be at equilibrium, you could probably apply chain rule, and come up with a scheme, where there would be a partial derivative that is essentially the compressibility factor.