This is not CADENCE or anything fancy, I just used LTSPICE to illustrate the concept.
I took measurements using the cursors, on the zero crossing of each signal (both rising or both falling, you can also use the peak values).
You can also use the differential measurement of the two cursors which will give the answer without manual calculation. Then, the difference
between the two measured on the zero-crossing (see figure), is your phase difference in terms of time, the one I called Tm. The two at
the top measured on the same sinusoidal is the period, denoted T. The period can also be calculated
T=1/f. With the time difference and
the period we can get the phase by taking the ratio between the two and multiply by 360 degrees. Hence,
Phase = (Tm/T)*360°.
I used a phase difference of 90° and a frequency of 10kHz. Figure:
So Tm = 50µs - 25µs = 25µs, and T = 125µs - 25µs = 100µs.
Phase = 360°(25µ/100µ) = 90°
I hope this helped.