Output:
Number of loops: 1251
Not paused:     0
Time delta is : 60.01318955421448

#!/usr/bin/env python

import time
import pause

frequency = 30 # Hz
period = (1.0/frequency)*1000

timeToRun = 1 # how many minutes to run
t_end = time.time() + 60 * timeToRun # run for timeToRun minutes

notPaused = 0
numRuns = 0

elapsedDiffList = []

startTime = time.time()
while time.time() <= t_end:
    timeNowMilli = time.time_ns()/1000000 # time from nanoseconds to milliseconds
    timeEndMilli = time.time_ns()/1000000

    pause.milliseconds(1)

    elapsedDiff = timeEndMilli - timeNowMilli

    if elapsedDiff < period:  # done before our schedule -- pause awhile
        timeToPause = period-elapsedDiff
        pause.milliseconds(timeToPause)
    else:  # took longer than scheduled -- send next message right away without pause
        elapsedDiffList.append(elapsedDiff)  # incase I get an extra long loop
        notPaused += 1
    numRuns += 1

endTime = time.time()
time_delta = (endTime-startTime)
print()
print("Number of loops: " + str(numRuns))
print("Not paused:    ", str(notPaused))
print('Time delta is : ' + str(time_delta))
print(*elapsedDiffList, sep=", ")

import time

start = time.perf_counter()
end_time = start + 60
count = 0

for division in range(1800):
    while time.perf_counter() < start + division/30:
        pass
    count = count + 1
elapsed = time.perf_counter() - start
print(f'Count {count} Elapsed {elapsed}')

Output:
Count 1800 Elapsed 59.966831974

while time.perf_counter() < start + division/30: